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Impact of Heavy Sediments at Shaft Bottom on Loss of Shear and Bearing Capacity of Drilled Pier Foundations

Permanent Link: http://ufdc.ufl.edu/UFE0022698/00001

Material Information

Title: Impact of Heavy Sediments at Shaft Bottom on Loss of Shear and Bearing Capacity of Drilled Pier Foundations
Physical Description: 1 online resource (98 p.)
Language: english
Creator: Swick, James
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2008

Subjects

Subjects / Keywords: bearing, bentonite, caisson, drilled, end, pier, shaft, slurry
Building Construction -- Dissertations, Academic -- UF
Genre: Building Construction thesis, M.S.B.C.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: Drilled shaft construction techniques have developed from field experience and engineering test results. One common belief among many drilled shaft contractors and engineers is that shaft concrete will displace the slurry and sand at the base of the shaft because it has a higher unit weight than the slurry. This principle is accurate to a point; the slurry in the shaft is displaced out of the top of the hole because the concrete is placed starting at the tip of the shaft. However, the sand that has settled on the bottom of the shaft is pushed into the corners of the cylinder and stay there after the concrete is placed. This causes a deformation in the tip of the shaft concrete and reduces end bearing area and side shear near the tip of the shaft. The intent of this research was to identify the effects of increasing sand content levels on the formation of concrete near the tip of the shaft. The suspected effect will be a decrease in the end area of the shaft resulting in a loss of shear and bearing. This will occur when the viscous fluid becomes trapped in the corners of the drilled shaft forming a bullet shaped tip at the bottom of the shaft. A literature review of prior research in the field of drilled shaft construction techniques showed that there was no existing model to test the researcher's theory, so such a model and experiment was created. The study required the development of a miniature drilled shaft model and the construction implements needed to replicate standard construction techniques used during the construction of a drilled shaft. This model allowed the researchers to determine the effects of varying sand contents present in the slurry on the formation of concrete near the shaft tip. The model tests showed a sand content of 4%, set as a maximum by FDOT, results in a loss of almost 3% of the side shear capacity within the bottom diameter. The bearing and structural strength of the shaft near the tip will be only about 30% of the theoretical values. This reduction of surface area, bearing area, and structural strength represents a significant loss for a drilled shaft with 4% slurry sand content. The author suspects that the decrease in the load bearing capacity will be exacerbated as more variables are introduced to the construction of drilled shafts. Therefore, the reduction in the load bearing capacity of the drilled shaft from slurry with a sand content of 4% is not acceptable.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by James Swick.
Thesis: Thesis (M.S.B.C.)--University of Florida, 2008.
Local: Adviser: Minchin, Robert E.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2010-12-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2008
System ID: UFE0022698:00001

Permanent Link: http://ufdc.ufl.edu/UFE0022698/00001

Material Information

Title: Impact of Heavy Sediments at Shaft Bottom on Loss of Shear and Bearing Capacity of Drilled Pier Foundations
Physical Description: 1 online resource (98 p.)
Language: english
Creator: Swick, James
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2008

Subjects

Subjects / Keywords: bearing, bentonite, caisson, drilled, end, pier, shaft, slurry
Building Construction -- Dissertations, Academic -- UF
Genre: Building Construction thesis, M.S.B.C.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: Drilled shaft construction techniques have developed from field experience and engineering test results. One common belief among many drilled shaft contractors and engineers is that shaft concrete will displace the slurry and sand at the base of the shaft because it has a higher unit weight than the slurry. This principle is accurate to a point; the slurry in the shaft is displaced out of the top of the hole because the concrete is placed starting at the tip of the shaft. However, the sand that has settled on the bottom of the shaft is pushed into the corners of the cylinder and stay there after the concrete is placed. This causes a deformation in the tip of the shaft concrete and reduces end bearing area and side shear near the tip of the shaft. The intent of this research was to identify the effects of increasing sand content levels on the formation of concrete near the tip of the shaft. The suspected effect will be a decrease in the end area of the shaft resulting in a loss of shear and bearing. This will occur when the viscous fluid becomes trapped in the corners of the drilled shaft forming a bullet shaped tip at the bottom of the shaft. A literature review of prior research in the field of drilled shaft construction techniques showed that there was no existing model to test the researcher's theory, so such a model and experiment was created. The study required the development of a miniature drilled shaft model and the construction implements needed to replicate standard construction techniques used during the construction of a drilled shaft. This model allowed the researchers to determine the effects of varying sand contents present in the slurry on the formation of concrete near the shaft tip. The model tests showed a sand content of 4%, set as a maximum by FDOT, results in a loss of almost 3% of the side shear capacity within the bottom diameter. The bearing and structural strength of the shaft near the tip will be only about 30% of the theoretical values. This reduction of surface area, bearing area, and structural strength represents a significant loss for a drilled shaft with 4% slurry sand content. The author suspects that the decrease in the load bearing capacity will be exacerbated as more variables are introduced to the construction of drilled shafts. Therefore, the reduction in the load bearing capacity of the drilled shaft from slurry with a sand content of 4% is not acceptable.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by James Swick.
Thesis: Thesis (M.S.B.C.)--University of Florida, 2008.
Local: Adviser: Minchin, Robert E.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2010-12-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2008
System ID: UFE0022698:00001


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1 IMPACT OF HEAVY SEDIMENTS AT SH AFT BOTTOM ON LOSS OF SHEAR AND BEARING CAPACITY OF DR ILLED PIER FOUNDATIONS By JAMES JACKSON SWICK III A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLOR IDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN BUILDING CONSTRUCTION UNIVERSITY OF FLORIDA 2008

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2 2008 James Jackson Swick III

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3 To my wife, Katie; my pillar of support. To my mother and father who ga ve me a foundation to work from and gave me the courage to believe in myself.

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4 ACKNOWLEDGMENTS I thank Dr. Crapps for the opportunity to lear n about drilled shaft inspection techniques, and the m aterials/equipment, and experience that he personally contributed to my research. I also thank Dr. Minchin for his guidance and sup port in the endeavor of conducting my research and the experience that he contributed to my studies. In addition, I would like to extend my thanks to Richard and Judie Furman for their su pport and for providing fa cilities in which to conduct my research.

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5 TABLE OF CONTENTS page ACKNOWLEDGMENTS...............................................................................................................4 LIST OF TABLES................................................................................................................. ..........7 LIST OF FIGURES.......................................................................................................................10 ABSTRACT...................................................................................................................................11 CHAP TER 1 INTRODUCTION..................................................................................................................13 1.1 Overview...........................................................................................................................13 1.2 Statement of the Problem.................................................................................................. 17 1.3 Objective of the Study......................................................................................................18 1.4 Hypothesis........................................................................................................................18 1.5 Research Methodology.....................................................................................................19 1.5.1 Theoretical Framework.......................................................................................... 19 1.5.2 Delineation of the Research Problem..................................................................... 19 1.6 Outline..............................................................................................................................19 2 LITERATURE REVIEW.......................................................................................................21 2.1 Introduction............................................................................................................... ........21 2.2 Drilled Shafts............................................................................................................. .......21 2.2.1 Analysis................................................................................................................. .21 2.2.2 Inspection...............................................................................................................22 2.2.3 Construction with Bentonite Slurry........................................................................ 24 2.3 Summary...........................................................................................................................24 3 METHODOLOGY................................................................................................................. 25 3.1 Overview...........................................................................................................................25 3.2 Drilled Shaft Construction Equipment............................................................................. 25 3.3 Materials and Properties...................................................................................................30 3.4 Slurry Testing Equipment.................................................................................................31 4 ANALYSES AND RESULTS............................................................................................... 34 4.1 Overview...........................................................................................................................34 4.2 Concrete Properties...........................................................................................................36 4.3 Sand Analysis.............................................................................................................. .....37 4.4 Concrete Surface Area Results......................................................................................... 45 4.5 Concrete Displacement Results........................................................................................ 47

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6 5 SUMMARY, CONCLUSIONS AND RECOMENDATIONS.............................................. 52 5.1 Summary...........................................................................................................................52 5.2 Conclusions.......................................................................................................................53 5.3 Recommendations.............................................................................................................54 APPENDIX A CONCRETE CYLINDER DATA.......................................................................................... 56 B CONCRETE CYLINDER AREA DATA.............................................................................. 83 LIST OF REFERENCES...............................................................................................................95 BIOGRAPHICAL SKETCH.........................................................................................................98

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7 LIST OF TABLES Table page 3-1 FDOT specified slurry properties (fresh water) ................................................................. 31 4-1 Tested slurry properties......................................................................................................35 4-2 White sand sieve analysis.................................................................................................. 43 4-3 Black sand sieve analysis...................................................................................................44 4-4 Average surface area data..................................................................................................46 4-5 Cumulative displacem ent analysis data ............................................................................. 48 A-1 Sand content control, cylinder #1................................................................................... 57 A-2 Sand content control, cylinder #1................................................................................... 58 A-3 Sand content 1%, cylinder #1......................................................................................... 59 A-4 Sand content 1%, cylinder #2......................................................................................... 60 A-5 Sand content 1%, cylinder #3......................................................................................... 61 A-6 Sand content 1%, cylinder #4......................................................................................... 62 A-7 Sand content 2%, cylinder #1......................................................................................... 63 A-8 Sand content 2%, cylinder #2......................................................................................... 64 A-9 Sand content 2%, cylinder #3......................................................................................... 65 A-10 Sand content 2%, cylinder #4......................................................................................... 66 A-10 Sand content 4%, cylinder #1......................................................................................... 67 A-11 Sand content 4%, cylinder #2......................................................................................... 68 A-12 Sand content 4%, cylinder #3......................................................................................... 69 A-13 Sand content 4%, cylinder #4......................................................................................... 70 A-14 Sand content 8%, cylinder #1......................................................................................... 71 A-15 Sand content 8%, cylinder #2......................................................................................... 72 A-16 Sand content 8%, cylinder #3......................................................................................... 73

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8 A-17 Sand content 8%, cylinder #4......................................................................................... 74 A-18 Sand content 16%, cylinder #1....................................................................................... 75 A-19 Sand content 16%, cylinder #1....................................................................................... 76 A-20 Sand content 16%, cylinder #2....................................................................................... 77 A-21 Sand content 16%, cylinder #2....................................................................................... 78 A-22 Sand content 16%, cylinder #3....................................................................................... 79 A-23 Sand content 16%, cylinder #3....................................................................................... 80 A-24 Sand content 16%, cylinder #4....................................................................................... 81 A-25 Sand content 16%, cylinder #4....................................................................................... 82 B-1 Sand content control, cylinder #1................................................................................... 84 B-2 Sand content 1%, cylinder #1......................................................................................... 85 B-3 Sand content 1%, cylinder #2......................................................................................... 85 B-3 Sand content 1%, cylinder #3......................................................................................... 86 B-4 Sand content 1%, cylinder #4......................................................................................... 86 B-5 Sand content 2%, cylinder #1......................................................................................... 87 B-6 Sand content 2%, cylinder #2......................................................................................... 87 B-7 Sand content 2%, cylinder #3......................................................................................... 88 B-8 Sand content 2%, cylinder #4......................................................................................... 88 B-9 Sand content 4%, cylinder #1......................................................................................... 89 B-10 Sand content 4%, cylinder #2......................................................................................... 89 B-11 Sand content 4%, cylinder #3......................................................................................... 90 B-12 Sand content 4%, cylinder #4......................................................................................... 90 B-13 Sand content 8%, cylinder #1......................................................................................... 91 B-14 Sand content 8%, cylinder #2......................................................................................... 91 B-15 Sand content 8%, cylinder #3......................................................................................... 92

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9 B-16 Sand content 8%, cylinder #4......................................................................................... 92 B-17 Sand content 16%, cylinder #1....................................................................................... 93 B-18 Sand content 16%, cylinder #2....................................................................................... 93 B-19 Sand content 16%, cylinder #3....................................................................................... 94 B-20 Sand content 16%, cylinder #4....................................................................................... 94

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10 LIST OF FIGURES Figure page 1-1 Typical drilled shaft cross section...................................................................................... 13 1-2 Slurry action inside of excavation...................................................................................... 16 1-3 Theoretical concrete shape with anomalies....................................................................... 17 2-1 Series of photos of shaft inspection device........................................................................ 23 3-1 Acrylic cylinders with stand.............................................................................................. 25 3-2 Series of slurry equipment photos...................................................................................... 26 3-3 Series of tremie photos.................................................................................................... ...27 3-4 Hydraulic extrusion system................................................................................................27 3-5 Concrete cylinder displacement......................................................................................... 28 3-6 Surface area voids at cylinder tip: 4 % sand content, cylinder #1......................................29 4-1 Slurry unit weight vs. sand content.................................................................................... 35 4-2 Estimated time for particle free fall in water and slurry .................................................... 40 4-3 Rate of sand fallout............................................................................................................41 4-4 Rate of sediment buildup in a 100ft shaft.......................................................................... 42 4-5 Grain size analysis........................................................................................................ .....45 4-6 Concrete cylinder displacement profile............................................................................. 49 4-7 Displacement profile near the tip of the concrete cylinder ................................................ 50 4-8 Series of photos of cast concrete cylinders. ....................................................................... 51

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11 Abstract of Thesis Presen ted to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science in Building Construction IMPACT OF HEAVY SEDIMENTS AT SH AFT BOTTOM ON LOSS OF SHEAR AND BEARING CAPACITY OF DR ILLED PIER FOUNDATIONS By James Jackson Swick III December, 2008 Chair: Edward R. Minchin Jr. Major: Building Construction Drilled shaft construction t echniques have developed from field experience and engineering test results. One common belief among many drilled shaft contractors and engineers is that shaft concrete will disp lace the slurry and sand at the base of the shaft because it has a higher unit weight than the slurry. This principle is accurate to a point; the slurry in the shaft is displaced out of the top of the hole because the concrete is placed st arting at the tip of the shaft. However, the sand that has settled on the bottom of the shaft is pushed into the corners of the cylinder and stay there after the concrete is placed. This causes a deformation in the tip of the shaft concrete and reduces end bearing area and side shear near the tip of the shaft. The intent of this research was to identif y the effects of increasi ng sand content levels on the formation of concrete near the tip of the shaft. The suspected effect will be a decrease in the end area of the shaft resulting in a loss of shear and bearing. This will occur when the viscous fluid becomes trapped in the corners of the drille d shaft forming a bullet shaped tip at the bottom of the shaft. A literature review of prior research in the field of drilled shaft construction techniques showed that there was no existing model to test the researchers theory, so such a model and experiment was created. The study required the development of a miniature drilled shaft model

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12 and the construction implements needed to rep licate standard construc tion techniques used during the construction of a drilled shaft. This model allowed the researchers to determine the effects of varying sand contents pr esent in the slurry on the forma tion of concrete near the shaft tip. The model tests showed a sand content of 4% set as a maximum by FDOT, results in a loss of almost 3% of the side shear capacity within the bottom diameter. The bearing and structural strength of the shaft n ear the tip will be only about 30% of the theoretical values. This reduction of surface area, bearing area, and structur al strength represents a significant loss for a drilled shaft with 4% slurry sa nd content. The author suspects that the decrease in the load bearing capacity will be exacerbated as more va riables are introduced to the construction of drilled shafts. Therefore, the reduction in the load bearing capacity of the drilled shaft from slurry with a sand content of 4% is not acceptable.

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13 CHAPTER 1 INTRODUCTION 1.1 Overview What is a drilled shaft? A drilled shaft is the deep foundation element of a support structure used in both terrestrial and marine environments. It is composed of concrete, rebar, and an in-situ form drilled out of the earth (Figure 1-1). Typical structures employing the use of drilled shafts for foundation support are br idges and high-rise buildings. Figure 1-1. Typical drilled shaft cross sect ion (Federal Highway Administration 2008). The force driving the industry to use more drilled shafts is that properly designed and constructed drilled shafts provide economical alternative for suppor ting large vertical and lateral loads. Other advantages of usi ng drilled shafts are that they are highly resistant to scour,

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14 construction does not generate damaging ground vibrations, and th ey develop high skin friction in addition to end bearing capacity (Hatch 2000). The drilled shaft is capable of supporting huge loads compared to its relative size and complexity a nd a single shaft can be used instead of a bent consisting of multiple piles to support the entire load of a column (Hatch 2000). In addition, under certain soil conditions such as clayey marl, drilled shafts are easier to install than the commonly used driven pile (Ted Holmes, personal communication, May 1, 2008). This is because unlike the driven pile, which must overc ome the resistance force of the soil to progress to the specified depth, the drille d shaft process utilizes a cutting action to overcome the material that is obstructing the drilling to ol. This cutting action alleviat es the problems caused by the cohesive forces inherent to the cl ayey marl that inhibit efficient pi le driving. They also serve as one of the few alternatives to driven piles and the destructive vibrations generated during their installation that cause damage to surr ounding structures in urban areas. A contractors field experience with drilled shaft constructio n techniques can provide an abundance of information that can by used to improve the installation and design methods. However, this experience extends little beyond th e initial placement of the drilled shaft when many of the problems with the construction technique or design have yet to present themselves. In spite of the significant amount of data that has been gather ed on the construction of drilled shafts, there remain significant uncertainties in predicting the affects of construction techniques on the field behavior of drilled shafts. One area of concern is the structural integrity of the shaft and how it may be affected by various construction techniques. There is a sign ificant possibility that a shaft may be approved for concrete placement and yet result in a concrete shaft with significant imperfections. This is possible because of the various inspection methods used to determine whether the shaft meets the

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15 specifications prior to concrete placement. The reliance upon the results of drilled shaft inspections varies according to the requirements en forced by the project owner. The results of these inspections, and the varying levels of importance placed upon them can have a significant impact on the drilled shaft contractors motivatio n to ensure that they are constructing a shaft that meets all of the requirements prior to concrete placement. This research focuses specifically on the botto m cleanliness specifications of a drilled shaft and the effect that they have on the performan ce of the shaft. The Florida Department of Transportation (FDOT) requires the contractor to verify the botto m cleanliness of a drilled shaft and various slurry properties before placement of concrete in a wet shaft. The component of construction analyzed in this rese arch concerns only the properties of the slurry and their effects on the formation of the concrete. 1.1.1 Properties of Slurry Slurry is a drilling fluid that is used during the construction of a drilled shaft and serves multiple purposes. During the excavation of a wet shaft, slurry is added to fill the void created in the earth as the drilling operation progresses. The reason that slurry is used to fill this void is because it maintains a higher densit y than water and crea tes a positive head pressure in the shaft exerting an outward pressure on the surrounding soil. Minerals slurries also form a filter cake that helps provide stability to the shaft excavation. These effects st abilizes the shaft and prevents cave-ins below the natural water table caused by water intruding into the shaft from the surrounding environment (Figure 1-2).

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16 Figure 1-2. Slurry action inside of excavation (Duncan 2002). Bentonite is a natural mineral that is mixed w ith water forming a drilling fluid referred to as slurry. The Bentonite slurry has a higher visc osity and density than water which enables it to keep small particulate matter in suspension fo r a limited amount of time. The ability of Bentonite slurry to keep detritu s in suspension provides the contra ctor an opportunity to separate the material suspended in the slurry and rem ove it from the excavation so that it does not adversely affect the performance of the shaft. Bentonite is a sodium montmorillonite and ex hibits thixotropic properties when combined with water. The thixotropic properties of the slurry are a result of bonds formed between the clay particles. In the presence of wa ter, the clay particles separate, forming a suspension of thin, plate-like pa rticles. The particles have a negative charge on the surface and a positive charge on the edge. A gel is formed through the three-dimensional bonding of the negative faces with the positive edge s. The bonds are weak, so they are easily broken by agitating the slurry. Th e bonds reform as the slurry is allowed to remain still (Reese and Tucker 1985).

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17 1.2 Statement of the Problem Many contractors and engineers working in the drilled shaft industry be lieve that the shaft concrete will displace th e slurry because it has a higher unit weight than the slurry. However, when the sand content reaches a certain level, the viscous fluid will be trapped in the corners of the drilled shaft forming a bullet shaped tip at the bottom of the shaft. This results in a reduced end area, which reduces the end bearing, and the sh aft side resistance is destroyed near the pile tip. These conditions place the primary compon ent of the foundation structure in a position susceptible to critical failure due to a loss of load bearing capac ity. Figure 1-3 illustrates the expected condition of the concrete resulting from an accumulation of sediment on the base of the shaft prior to concrete placement. Figure 1-3. Theoretical concre te shape with anomalies There is a significant need to quantify the f actors that led to the possible failures and degradation of drilled shaft bearing capacity. Research into the various aspects of drilled shaft construction techniques will aid in the determina tion of these causes. This study will contribute

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18 to the body of research that has aided in the improvement of desi gn and construction practices of drilled shaft construction. 1.3 Objective of the Study This study will determ ine the e ffects of various slurry sand contents on the formation of concrete in the drilled shaft. The sand contents analyzed ranged from 1 to 16%. The study will quantify what effects on the concrete placement in the shaft and determin e the sand content when present in the slurry, reduces the end bearing ar ea and side-shear area ne ar the tip of a model shaft. The outcome of this res earch will provide an accurate repr esentation of the effects that varying sand contents of slurry have on the placement of concrete after it has passed bottom cleanliness inspections. The data will also de termine whether the FDOT specification of 4% allowable sand content is above or below the actual limit required for successful concrete placement in a drilled shaft. The scope of this research is limited to the analysis of slurry sand content only, and the effects generated by possible sedimentation of sand suspended in the slurry. The information gathered from this model will analyze a single f actor that may affect overall shaft performance. There are numerous variables not represented in the model and are cond itional to drilled shaft construction that may likewise increase the deforma tion of the concrete in addition to the affects of sedimentation of sand from the slurry. The limitations of this research do not allow for the various analysis required to test the multitude of variables that have an affect on concrete formation in drilled shafts. 1.4 Hypothesis Heavy sedim ents at shaft bottom result in a lo ss of shear and bearing. This deformity will resemble a round bullet shaped tip at the end of the pile resulting in the loss of end area and side shear resistance near the shaft tip.

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19 A target slurry sand content percentage exists that will reduce the probability of a concrete deformity due to sedimentation. Ideally, slurry would have a zero sand content percentage prior to concrete placement. However, due to the cons traints of the work environment that goal is not realistic. A sand content ratio exists that balances the effort required to de-sand the slurry and the risk of sedimentation from a high sand content percentage. 1.5 Research Methodology 1.5.1 Theoretical Framework The proposed sedim entation caused by the susp ension of sand in the slurry occurs during the estimated two hour time span between the bottom cleanliness inspection and approval for concrete placement and the act ual placement of concrete. Under ideal conditions, it takes approximately two hours of preparation for the dr illing contractor to sw itch from the drilling operation to concrete placement. It is during this time the sand that is suspended in the slurry will settle to the base of the shaft. 1.5.2 Delineation of the Research Problem The resea rch will use model-based experiments to collect data on the formation of concrete after a two-hour period has expired allowing for po ssible sedimentation of medium to fine sands in Bentonite slurry. The data collected will be analyzed to determine whether bottom cleanliness is affected by slurry sedimentation and the aff ects it has on the area of th e shaft tip, side shear, and end bearing. Recommendations will be given acco rding to the result of the data analysis. 1.6 Outline Chapter 2 represents a literature review of pub lications and res earch th at has contributed to the field of drilled shaft analysis and inspecti on techniques. This chapter will also provide a synopsis of past research on the affect of constr uction techniques on the load bearing capacity of drilled shafts.

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20 Chapter 3 explains the methodology used to de velop the information needed to accurately categorize the effects of sedimentation on the form ation end bearing and si de shear capacity of drilled shafts. Chapter 4 is the analysis and explanation of the information collected during the research. Also covered in this chapter will be an analysis of the materials used du ring the research and any possible affects that they may have had on the outcome of the research. Chapter 5 is the final chapter of the thesis covering the conclusions drawn from the data analysis conducted in Chapter 4 as well as any possible recomme ndation for future research and exploration into the effect of sediment ation on drilled shaft construction.

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21 CHAPTER 2 LITERATURE REVIEW 2.1 Introduction This chapter will dis cuss the standards of dr illed shaft design, analysis, and construction methods and the development of inspection proce dures. The opinions of industry professionals on the limitations of drilled shaft construction will also be discussed. In addition, this chapter will provide an overview of relevant research in production and utility of slurry as a drilling fluid. 2.2 Drilled Shafts Projec t owners and designers are increasing the use of drilled shafts as familiarity with this type of construction and the related benefi ts develop. The advantag es presented by the use of drilled shafts have driven the industry to investigate the applications for this form of construction. In addition, the increase in use ha s helped foster the confidence professionals have in the performance of dri lled shaft cons truction. 2.2.1 Analysis Drilled shaft use on highway projects doubled from 1990 to 2000 (Hatch 2000). The increase in drilled shaft construction is due in par t to the advancement of drilled shaft construction technology and the reliability of insp ection techniques. Init ially the industry was reluctant to use drilled shafts because of the inability to verify the constructed load bearing capacity of the shaft. The deve lopment of methods to determine the actual load bearing capacity of drilled shafts fostered detailed analyses of the effect of construction techniques and inspection procedures on the capacity of drilled shafts. However, significant aspects of drilled shaft construction are still under debate For instance, a national standard for the bottom cleanliness of drilled shafts does not exist. In addition, ther e is a substantial variation across the nation on

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22 whether drilled shafts are designe d for side shear resistance or end bearing capacity or both. The conservative design parameters used to account for the effects caused by faulty construction procedures have no theoretical basis and differ throughout th e world (Abdrabbo and Abouseeda 2002). The FDOT drilled shaft designs take into account bot h the load bearing capacity afforded by the side shear resistance and end bearing capac ity of the drilled shaf t (FDOT 2000). This is fortunate because drilled shafts have a greater potential to deve lop high load bearing capacities from both side shear resistance a nd end-bearing resistance in the so fter soils present in Florida (Greenlee 2004). If the FDOT di d not allow designs to include both side shear and end-bearing then the resulting designs would certa inly be over designed and costly. 2.2.2 Inspection To ensure the reliability of the end bearing th at is used to achieve th e total load bearing capacity of the drilled shaft the FDOT requires all drilled shafts to pass a bottom cleanliness inspection. This inspection requires that at a minimum 50% of the shaft bottom have less than one-half inch of sediment and that the maximum depth of sediment anywhere on the base of the shaft does not exceed one and one-half inches at the time of concrete placement (FDOT 2000). This inspection is required for all shafts designe d using a drilling fluid. To ensure that the contractor meets the requirements for the bottom cleanliness test the FDOT requires the contractor to use a shaft inspect ion device (SID) to indict the de pth of sediment on the base of the shaft. The SID allows the inspector to visua lly inspect and record th e depth of sediment at the base of the shaft. This is accomplished via a sealed high-resoluti on camera mounted atop a steel cylinder with 200 pounds of ballast that slices through the loose material indicating the depth of debris on the bottom of the shaft along a scale mounted in view of the camera, see Figure 2-1 (David Crapps, pers onal communication, August 2, 2008).

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23 A B C Figure 2-1. Series of photos of shaft inspection device. A) inspec tion photo, B) camera and bell, C) bottom of inspection bell (c redit card shown for scale. The SID inspection method provides an accurate record of the depth of sediment at the bottom of the shaft. However, the time that passes between the time of the inspection and the placement of concrete can result in the introduc tion of significant variables to the bearing capacity of the drilled shaft. The variable st udied in this research is the accumulation of sediment on the base of the shaft. Using a know n sand content (S.C.) of slurry the depth of sedimentation (Ds) in inches of a 100 foot shaft can be calculated dur ing a two hour period by Ds, in. = 1.77(S.C., %)1.6 (Crapps 2005). The soft bottom created by the sedimentation can result in a downward compression of several inches be fore the disturbed material has compressed sufficiently to fully transmit the load to the lo wer undisturbed soil (Oster berg 2000). The safety factor for allowable overall shaft settlement is clearly decreased when the affects on shaft movement due to sedimentation and soft bottoms are combined.

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24 2.2.3 Construction with Bentonite Slurry Bentonite slurry is a very effective tool that has enabled con tractors to construct drilled shafts under conditions that would have previously rendered the f eat impossible. Nevertheless, the use of slurry still introduces variables to th e construction environment that are not apparent when working in dry shaft conditions. Under certain conditions, Bentonite may fail to keep detritus in suspension developing increased sediment on the bottom of the shaft and reduce side shear capacity due to a heavy buildup of filter cake on the wall of the shaft. Filter cake develops as a byproduct from the slurry as it develops an impermeable layer on the walls of the shaft to limit the seepage of the slurry into the surround ing soil and prevent the intrusion of ground water into the excavation. The bottoms of the shaft should be over r eamed if a 12 hour time limit is exceeded (FDOT 2000). The failure of the slurry to keep the detritus in su spension is a result of the improper mixing of the slurry and a failure to maintain the condition of the slurry prior to concrete placement (Reese and Tucker 1985). A proper mixing procedure and maintenance of the slurry once the excavation has started is essential to constructing a drilled shaft with a reliable load bearing capacity free of any major defects or flaws. 2.3 Summary The use of drilled shafts has increased signifi can tly within the last two decades due to an accumulation of data on the actual load bearing capaci ty of drilled shafts and the ability to verify the conditions of the excavation prior to concrete placement. Theses factors have contributed to the increase in confidence that designers and contr actors have in the drilled shaft as a reliable and economical foundation structure that can be constructed in a variety of geological conditions. The drilled shaft construction industr y is still in need of a theore tical basis for design parameters and construction methods so that the most accurate specifications for the load bearing capacity of drilled shaft in a variety of geologi cal conditions can be established.

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25 CHAPTER 3 METHODOLOGY 3.1 Overview Specialized equipm ent was required to match the construction techniques commonly used by drilled shaft construction professionals. A re adily accessible source for the equipment was not available for the research a nd it was necessary to fabricate th e equipment that would enable the research to be conducted on a scale appropriate to the research requirements. The resulting equipment designs resulted in an environment that was very near to drilled shaft construction conditions. 3.2 Drilled Shaft Construction Equipment The m ost critical aspect of the research procedure was the development of a mold that would represent a perfectly construc ted drilled shaft, allow for reus e, and aid in the extraction of the cast concrete cylinders. The preferred material would also enable the researcher to visually observe the affects of sedimentati on on the formation of concrete in the artificial drilled shafts. To meet these requirements 5 6 0.25 acrylic cylinders were used in conjunction with a 6 2 acrylic plug, (Figure 3-1). The acrylic plug required some m achining for the installation of rubber o-rings to create a removable water proof s eal that would mate to the acrylic cylinder. Figure 3-1. Acrylic cylinders with stand.

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26 Bentonite slurry production was conducted in a 100-gallon trough in conjunction with a submersible pump. The pump required modi fication to allow connections to multiple apparatuses designed for circulati ng the slurry, introduction of Bent onite, and transfer of slurry from the trough to the cylinders. It was necessa ry to limit the pumps run time to 4 hours due to the inability of the sl urry to dissipate the heat genera ted by the pump. The introduction of additional Bentonite to the slurry was acco mplished using a hopper constructed from PVC (polyvinyl chloride) pipe, (Figure 3-2). The inte nt of the hopper design was to create a vacuum inside of the vessel that would draw the Bent onite into a high-pressure water jet from the discharge of the pump that would mi x the Bentonite into the slurry. A B Figure 3-2. Series of slurry equipment photos. A) slurry, B) hoppe r and pump system. To allow for probable sedimentation that occurs during construction, two hours were allotted between placement of slu rry in the acrylic cylinders and placement of concrete. This selected time interval (two hours) represents the estimated time required for removal of inspection the inspection equipmen t, installation of the reinforc ing cage, and placement of the tremie and other preparations prior to concrete placem ent (David Crapps, personal communication, May 13, 2008).

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27 Placement of concrete in the cylinders was accomplished using a tremie based on standard construction designs (Figure 3-3). The tremie was designed to maintain a significant positive head pressure to displace the slu rry as concrete was placed. To pr event the flow of concrete until the base of the tremie was positioned within one-inch from the base of th e cylinder a sacrificial tremie plug was used that prevented slurry from contaminating the concrete prior to placement. A B C Figure 3-3. Series of tremie photos. A) concrete placed using model tremie, B) tremie plug, C) tremie pipe with plug installed The cured concrete cylinder was extruded from the cylinder with sufficient pressure supplied by a hydraulic ram (Figure 3-4). The extruder incorporated a steel frame that horizontally secured the cylinde r, a two-inch hydraulic ram with a 36-inch stroke, and a hydraulic hand pump. This procedure enabled the researcher to overcome the substantial side shear of the hardened concrete and create a smooth extraction of the concrete from the cylinder. Figure 3-4. Hydraulic extrusion system

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28 After all the loose sand remaining on the out side of the cured concrete cylinder was removed the volume of the structural concrete that was left in place was determined. A volumetric analysis was conducted by measuring the amount of fluid displaced by the concrete as it was immersed in a fluid f illed container. The displaced fluid was captured in a 1000 ml graduated cylinder. The volume of displaced fluid was recorded according to the depth of immersed concrete in increments of inch near the tip and increments of two inches for the remainder of the cylinder, a dept h of 20 inches, (Figure 3-5). Figure 3-5. Concrete cylinder displacement The effect that the sedimentation had on the concrete cylinder was determined by quantifying the loss of contact area between the concrete cyli nder and the interior of the theoretical shaft. To determine the surface ar ea lost due to sedimentation the cylinder was encased in a 20 gauge vinyl sheet measuring 18 in ches by 24 inches. The loss in contact area between the vinyl and the concre te was clearly observable through this material. These areas were then recorded by tracing on the vinyl al ong the outside perimeter of the voids. The transparent material was then taken off of the c oncrete cylinder and laid over a template outlined with a 1-inch grid measuring 18 inches 24 inch es. The area representing the loss of contact area on the face of the shaft was then recorded by totaling the number of one inch squares

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29 present inside of the outlined concrete void. Figure 3-6, shows an example of the voids traced on the vinyl material using a dry erase marker and th en placed on top of the 18 24 inch grid. The area under the traced line repres ents the loss in contact area be tween the concrete cylinder and the vinyl sheet. Figure 3-6. Surface area voids at cyli nder tip: 4% sand content, cylinder #1 3.2.1 Testing Procedures The test procedures used to determ ine the sa nd content required to decrease end bearing and side shear area are. 1. Mix slurry: use increasing sand content percentages for each te st (1, 2, 4, 8, and 16%), keep in suspension until ready to place concrete 2. Place slurry in acrylic cylinders, allow two hours for sedimentation 3. Mix concrete 4. Place concrete using model tremie

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30 5. Let concrete cure for 36 hours 6. Extrude cast cylinder, photograph 7. Measure volume of concrete cylinder through displacement of fluid and compare to total theoretical volume 8. Measure area of shaft surface area and analyze affects on side shear The results of this test are outlined in Chapter 4. The test procedures used to determine the rate of sedimentation of a medium to fine sand in Bentonite slurry are: 1. Mix slurry use increasing sand content pe rcentages for each test (1, 2, 4, 8, and 16%) 2. Place slurry in six-inch acrylic cylinders 3. Measure settlement with time and record data The results of this test are outlined in Chapter 4. 3.3 Materials and Properties Sakrete Arena Natural Fine Sand was selected to research the suspension of a m edium to fine sand in slurry. The results of a sieve analysis of this sand can be found in Chapter 4. Also selected for analysis was a medium-to-fine sand that had been dyed black from Catskill Mountain Industries I, LLC (CMI). The results of a sieve analysis of th is sand can be found in Chapter 4. However, due to unaccounted properties, the settlement of the sand purchased from CMI was not comparable to the settlement rate of the sand purchased from Sakrete. The sand supplied by Sakrete was chosen for analysis because of the similarity to medium to fine sands in Florida and due to the observable sedimentation that occurred during suspension in slurry. Due to the conditions of the research scale, a fine-aggregate mortar mix was used to cast the concrete cylinders. A coarse aggregate material was not ne cessary for the purpose of the research or feasible given the scale of the model assuming that aggregate size does not exceed

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31 1/8 inch. Sakrete supplied the mortar mix re ferred to as Type-S Mortar/Stucco Mix. Also introduced to the mortar mix was additional Type 1 Portland cement supplied by Titan America to enhance the consistency and strength of the concrete. The propertie s of the concrete are outlined in Chapter 4. Bentonite and Attapulgite are the most commonly used additive to produce slurry in Florida. Bentonite was chosen for this resear ch. Colloid Environmen tal Technologies Company (CETCO) processed the Bentonite referred to as Super Gel-X and was de scribed as an Extra High Yield Drilling Fluid. The tested slurry properties are listed in Chapter 4. 3.4 Slurry Testing Equipment The inform ation provided in Table 3-1 outline s the characteristics required by the FDOT to use Bentonite slurry as a drilling fluid. Meas urement of these characteristics aids in the determination of the ability of the slurry to bui ld up filter cake and to hold detritus in suspension (Reese and Tucker 1985). Table 3-1. FDOT specified slurry properties (fresh water) Bentonite Slurry Items to be measured Range of Results Test Method Sand Content Density 4% maximum 64 73 pcf Volumetric Test Mud Density Balance Viscosity 28 40 sec. qt. Marsh Cone pH 8 to 11 pH Paper Strips The FDOT specifications require the slurry unit weight to be less than 75 pcf at the time of concrete placement. The sand content of the slurry prior to conc rete placement was tested using a sand content kit manufactured by Fann Instrument Company. The sand content kit includes Wash bottle (500 ml) Carrying case

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32 Sand content screen (200 mesh) Sand content funnel Sand content tube Sand contents of 4% and higher are expected to result in the deformation of concrete due to sedimentation that occurs during the two hours between placement of slurry in the cylinders and placement of concrete. The results of the sand content tests performed during the research can be found in Chapter 4. The density of the slurry was tested usi ng a Mud Balance Model 140 manufactured by Fann Instrument Company. The mud balance kit includes Lid Lead shot (vial) Fulcrum Plastice carrying case Cover screw Knife edge Rider Base with fulcrum The density of the slurry reveal s the level of contamination pres ent in the slurry. A density above 75 pounds per cubic foot (pcf) increases the possi bility that as the concrete is placed it will not be able to displace the slurry out of the shaft. The result s of the density tests performed during the research can be found in Chapter 4. The marsh funnel viscometer manufactured by Fann Instrument Company, measures the viscosity of the slurry. The vi scosity of the slurry serves as an indication of the level of contamination as well as the concentration of Bentonite present in the slurry. As the concentration of Bentonite present in the slurry increases the affect s of the clay-like properties of the slurry increase. This results in an increased ability of the slurry to keep detritus in suspension as well as decreased flow and circulation of the slurry.

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33 Common pH paper strips were used in the measur ement of the pH of th e slurry. The pH of the slurry must remain above seven on the pH scale; otherwise, th e consistency of the slurry will decrease resulting in a decrease in the ability of the slurry to pe rform its functions. Very little variation was noted in th e pH of the slurry due to the use of potable water in the production of slurry and the restricti on of foreign minerals in troduced to the slurry.

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34 CHAPTER 4 ANALYSES AND RESULTS 4.1 Overview Throughout the research, data was collected on the conditions affecting each set of concrete cylinders with sand contents of 1, 2, 4, 8, and 16%. The data recorded for each set of cylinders includes Slurry properties Concrete su rface area Concrete cylinder volume An analysis of this information yielded th e concrete cylinders sh ear area, structural volume, and the effects of sedimentation from sl urry. Also recorded was information concerning the properties of a typical sample of concrete and a sieve analys is of the sand mixed with the slurry. The information on the surface area and displacement of the concrete cylinders represented in this chapter is an average of the four test cylind ers that were made at each sand content of 1, 2, 4, 8, and 16%. The analysis of this information and the corresponding charts can be found in the following sections. 4.1.1 Bentonite Slurry Properties The Bentonite slurry used to test the effects of sedim entation on the placement of concrete in a model drilled shaft was mixed according to th e stipulations outlined by the FDOT for use as a drilling fluid with one exception. The excep tion to the FDOT requirements was the sand content of the slurry prior to concrete placement. This variable was introduced to study the effects that the varying sand cont ents would have when allowed to remain in suspension for two hours prior to concrete placement. The results of the consecutive slurry tests are recorded in Table 4-1.

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35 Table 4-1. Tested slurry properties Stage pH Unit Weight (lbs/ft^3) Sand Content (% by volume) Marsh Cone (seconds) Date Description of Concrete Surface Area Near the Tip 1 7.5 63.00 0 35.13 6/28/2008No measurable inclusions 2 7.5 64.50 1 35.69 6/30/2008<1-3 sq. inches lost 3 7.0 65.00 2 35.85 7/2/2008 <1-2 sq. inches lost 4 7.5 65.50 4 37.00 7/4/2008 5.0-10.5 sq. iches lost 5 7.5 75.50 8 35.13 7/6/2008 1.5-11.5 sq. inches lost 6 7.5 79.00 16 35.65 7/8/2008 19-23.5 sq. inches lost The data represented in Table 4-1 shows that th e slurry used for each test had a neutral pH and would have no effect on the ability of the slur ry to keep detritus in suspension. The neutral pH was achieved because the water used to mix the slurry was from a potable water source free of contamination that when present may have af fects on the performance of the slurry. It is expected that additional variables that affect the performance of the slurry are introduced in the field based upon the water source and its level of contamination. The relationship between the slurry unit weight and sand conten t is shown in Figure 4-1. 0 20 40 60 80 100 0%5%10%15%20% Sand Content (%)Unit Weight (pcf) Figure 4-1. Slurry unit weight vs. sand content The unit weight of the slurry is within the acceptable range outlined by the FDOT until a sand content of 8% is reached. The increase in the unit weight of the slurry beyond the acceptable range was a result of the increased density of the sand that was suspended in the

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36 slurry when the density of the slurry was measur ed. The cause of this change in density is known because of the level of control that was exercised during the production of the slurry. The sand content of the slurry was controlled so that the e ffects of specific sand content percentages could be tested. Using the marsh c one funnel test, the viscosity of the slurry was maintained between 35 and 37 seconds. The viscos ity maintained is within the range required by the FDOT for slurry use as a drilling fluid throug hout the duration of the rese arch. It is expected that altering the viscosity of the slurry would affect its ability to keep detritus in suspension, generating data with multiple variables. A s ynopsis of the effects of the sedimentation is recorded in the final column of Table 4-1. A reco rd of the specific effects of the increased sand contents on the structural capacity and surface area of the concrete cylinders can be found in the following sections. 4.2 Concrete Properties The type of concrete used in casting the conc rete cylinders was determ ined based upon the few basic requirements for the research. The concre te had to be readily available at the site in quantities of less than five cubic feet. The c oncrete had to contain aggregate less than 1/8th of an inch in diameter to accommodate the 1-inch diameter of the tremie pipe and it had to maintain shape after extrusion from the acrylic cylinder. Sakrete concrete described as Type S high strength mortar/stucco mix was selected for this model. This concrete contained no large aggregate since it was de termined to be unnecessary for an accurate determination of the effects of sedi ment on concrete deformation. Additional Type-1 Portland cement was used to increase the early st rength of the concrete and reduce the cure time required before extrusion from the acrylic cylinder A typical batch of co ncrete had a mixture of 33 quarts Sakrete, 16 quarts Type-1 cement, and 21 quarts water (for all four model cylinders). Since the concrete was not going to undergo a compression test, it only needed to cure long

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37 enough to maintain its original shape after it was cast in the acrylic cylinder. The unit weight of the concrete was determined to be 124.8 pounds per cubic foot (pcf). 4.3 Sand Analysis Initially a portion of the research was intended to test the sedim entation of a medium to fine sand supplied by both Sakrete and CMI. A sieve analysis of the sand provided by both suppliers yielded comparable results with less than 10% passing the number 80 screen in either sample. However, this approach was abandoned after it was determined that the sand supplied by the CMI differed in properties that were not measurable by the rese archer. These unknown properties enabled the CMI suppl ied sand to remain in suspension for more than 12 hours accumulating less than 1/16th of an inch of sediment at the base of the shaft. It is suspected that the black sand supplied by CMI had an interac tion with the thixotro pic properties of the Bentonite affecting the opposing polar reactions between the particles re sulting in the increased suspension time of the sand mixed with the slurry (reasoning from Reese and Tucker 1985). Following this reasoning, the sand supplied by Sakrete was naturally occurring and did not contain any artificial dyes lik e the sand supplied by CMI and was therefore a more likely representation of the soil condi tions in Florida. For this reason, only the sand supplied by Sakrete was used to attain the ta rget sand contents of 1, 2, 4, 8, and 16% in the slurry to test how each of the various sand contents affected the placement of concrete after twp hours had been allotted for possible sedimentation. A sedimentation study was conducted to determin e the rate of sedimentation of a medium to fine sand in Bentonite slurry. However, th is study revealed that the sand used in the study does not settle uniformly at the base of the shaf t. The sand settles on the base of the shaft at various rates in different areas of the cylinder forming sma ll conical shaped mounds that were not uniform in shape or size. The shape of sedimentation made it improbable to accurately

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38 determine the depth of sedimentation by measur ing the accumulated height of sand along the inside surface of the acrylic cylinder. Due to the non-uniform result s of the sedimentation analysis there was no data available from the te st to use for a determination of the rate of sedimentation of medium to fine sands in Bentonite slurry. The data that was used to support the conclusi ons of this research was taken from a study performed at the University of South Flor ida (Mullins and Ashmway 2005). Mullins and Ashmway prepared a report for the FDOT that include d the results of an indirect test on the rate of free fall of particles in slu rry. Crapps (2005) used theoretical relationships to estimate the time for particles to fall in a 100-f oot shaft with various fluids (Figure 4-2). The results of the tests performed by Mullins and Ashmway on sedime ntation are displayed in Figure 4-3. Crapps also used the data from Figure 4-3 from Mullins and Ashmway to determine the Figure 4-4 relationships. The data presented by Crapps (2005) shows that as the viscosity of the slurry increases, the time necessary to attain maximum appreciable sedi mentation increases for a given particle size. The data in Figure 4-4 also shows that the se diment buildup in two hours increases with sand content. From these results, it is apparent th at the two hours allotted for sedimentation is enough time for significant sedimentation to occur that may result in the de formation of the concrete that is placed for construction of the drilled shaft. These results show that the sand content of th e slurry is a critical factor in the bottom cleanliness of the drilled shaft prior to concrete placement. To pass the bottom cleanliness test required by the FDOT a minimum of 50% of the ba se of each shaft will have less than one half inch of sediment at the time of placement of the concrete (FDOT 2000). Figure 4-4 shows that even if the contractor is able to pass the bottom cleanliness inspecti ons required by the FDOT,

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39 within two hours at a 4% sand content in a 100 foot shaft, more than ten inches of sediment will have accumulated on the bottom of the shaft. Acco rding to the specifications of the FDOT this depth of sediment is not acceptabl e prior to placement of concrete. The data shown in Figure 4-4 illustrates that in order to meet the bottom cl eanliness inspections after two hours have elapsed from the initial bottom cleanliness inspections th e sand content of the slurry can be no higher than 0.4%.

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40 Figure 4-2. Estimated time for particle fr ee fall in water and slurry (Crapps 2005)

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41 Figure 4-3. Rate of sand fall out (Mullins and Ashmway 2005)

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42 Figure 4-4. Rate of sediment buildup in a 100ft shaft (Crapps 2005)

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43Table 4-2. White sand sieve analysis SOIL SAMPLE White Sand______ WT CONTAINER + DRY SOIL IN g 709.5 TEST NO. 1 Supplier Sakrete_ WT CONTAINER IN g 193.8 DATE 7/26/2008 _______________ WT DRY SOIL, Ws, IN g 515.7 SIEVE NO. SIEVE OPENING IN mm WT. SIEVE IN g WT SIEVE + SOIL IN g WT. SOIL RETAINED IN g PERCENT RETAINED CUMMULATIVE PERCENT RETAINED PERCENT FINER 4 4.750 427.20427.20 0.00 0.00 0.00 100.00 10 2.000 393.10393.90 0.80 0.16 0.16 99.84 40 0.425 310.40390.20 79.80 15.47 15.63 84.37 80 0.180 283.40677.10 393.70 76.34 91.97 8.03 100 0.150 284.10307.10 23.00 4.46 96.43 3.57 140 0.106 276.50289.10 12.60 2.44 98.88 1.12 200 0.075 266.20269.10 2.90 0.56 99.44 0.56 Pan n/a 281.40281.90 0.50 0.10 99.53 0.47

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44 Table 4-3. Black sand sieve analysis SOIL SAMPLE Black Sand WT CONTAINER + DRY SOIL IN g 778 TEST NO. 2 Supplier Catskill WT CONTAINER IN g 201.7 DATE 7/26/2008 Mountain Industries WT DRY SOIL, Ws, IN g 576.3 SIEVE NO. SIEVE OPENING IN mm WT. SIEVE IN g WT SIEVE + SOIL IN g WT. SOIL RETAINED IN g PERCENT RETAINED CUMMULATIVE PERCENT RETAINED PERCENT FINER 4 4.750 427.20 427.20 0.00 0.00 0.00 100.00 10 2.000 393.10 393.10 0.00 0.00 0.00 100.00 40 0.425 310.40 381.50 71.10 12.34 12.34 87.66 80 0.180 283.40 767.20 483.80 83.95 96.29 3.71 100 0.150 284.10 297.80 13.70 2.38 98.66 1.34 140 0.106 276.50 282.50 6.00 1.04 99.71 0.29 200 0.075 266.20 266.90 0.70 0.12 99.83 0.17 Pan n/a 281.40 281.60 0.20 0.03 99.86 0.14

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45 Sieve Analysis 0% 20% 40% 60% 80% 100% 0.010 0.100 1.000 10.000 Grain Size (mm)Percent Passing (%) White Sand Black Sand Figure 4-5. Grain size analysis 4.4 Concrete Surface Area Results From the concrete cylinder samples, data was obtained on the act ual area in contact between the outside of the concre te shaft and the inside of the shaft hole. This information represents the area used to calculate the side sh ear capacity of the drilled shaft. Therefore, by quantifying the reduction in th e surface area of the concrete cylinder an indication of the significance sedimentation has on th e side shear capacity of th e shaft can be provided. The results of this analysis are shown in Table 4-4.

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46 Table 4-4. Average surface area data Slurry Sand Content Area Lost in 1st 4 inches from tip (sq. inch) Shear area lost in 1st 4 inches from tip (%) Cumulative Area Lost (sq. inch) Cumulative Shear Area Lost (%) Control 2.50 3.62 4.50 1.30 1.00 3.38 4.89 3.38 0.98 2.00 1.25 1.81 1.50 0.43 4.00 7.75 11.22 9.88 2.86 8.00 10.50 15.20 21.88 6.33 16.00 34.50 49.94 194.25 56.24 The information provided in Table 4-4 clearl y shows that sedimentation of sand suspended in the slurry results in a signi ficant reduction on the shear area of the shaft near the tip. The reduction in the contact area between the concrete and the shaft hol e is a result of the sand that was trapped by the concrete during placement. Th e area lost on the control cylinder was a result of the failure to retrieve the saran wrap used to prevent the slurry from en tering the tremie pipe. This area lost was not a result of any sedimentatio n and the concrete in th e control cylinder filled the remaining available volume of the acrylic cylinder. In the mode l shafts having any sand content the sand was pushed to the sides of the sh aft as the concrete level rose in the cylinder creating a barrier between the conc rete and the shaft hol e. This creates a loss in shear capacity because the sand that is trapped between the concrete and the surf ace of the shaft hole represents no structural value and is equivalent to a void in the concrete. The surface area of the concrete cylinders affecting shear capac ity could not be determined from the displacement analysis that was conducte d on the shaft due to the amorous shape of the concrete cylinders created by displaced sand. Although the displacement analysis does provide an average structural radius of the concrete cyli nders, it does not represent the actual contact area between the concrete cylinde rs and the shaft hole.

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47 Prior to the placement of concre te in cylinder four at 8% sa nd content some concrete was lost due to a broken concrete mixer handle and additional concrete was required. The resulting concrete mix had a slump greater than the 200 mm target slump recommended by the FDOT for placement in drilled shafts. Unknown at the time of concrete placement, but later discovered in a review of literature materials, concrete with a high slump has an increased probability of displacing sand that has settled to the base of the shaft. This variable explains the cumulative shear area loss of only 4.05% for cy linder four compared to an average of 7.09% for cylinders 13. The results of this anomaly can be seen in th e decrease in shear area lost near the tip from 21.71% for 4% sand content to 19.18% for 8% sand cont ent. An average of cylinders 1-3 at 8% sand content result in a loss of 24.12% shear area near the tip of the shaft and an average of 7.09% overall loss of shear area. Also of note is the shear area lo st on the control cylinder. This anomaly is a result of the displacement of the plastic material used to seal the tremie plug. For all remaining test cylinders this material was recovered. However, it did re sult in a loss of shear area located 4-6 inches from the tip of the shaft. 4.5 Concrete Displacement Results Inform ation concerning various aspects of the amorphous shape of the concrete was interpreted based on the data colle cted on the volume of the concrete cylinders. This information included such matters as the average radius of an amorphous shape, the cross sectional profile of the cylinder, as well as a profile of the entire shaft consisting of individual cross sections along the length of the cylinder. This data provides de tails outlining the overall shape of the concrete cylinders in a way that that w ould otherwise only be available fr om a visual inspection of the concrete cylinders.

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48 The information provided in Table 4-5 represen ts an average of the properties recorded for the test cylinders placed at each sand content percentage. This data represents an overall observation that as the sand conten t percentage of the slurry in creases: the volume of the fluid displaced, average surface area, and the average radi us of the concrete cylinders decrease. When studying this data, the variation in cumulative volume seems minute. However, an analysis of the location of the volume lost on each cylinder depicts a situation that resulted in a decreased bearing capacity of the shaft. Table 4-5. Cumulative displacement analysis data Slurry Sand Content (%) Cumulative Displacement (ml) Cumulative Displacement (cu. inch) Average Radius (inch) Cumulative Area (sq. inch) Cumulative Volume (%) Control 7655.00 467.11 2.82 342.55 99.17 1.00 7695.00 469.55 2.72 343.44 99.43 2.00 7611.25 464.44 2.59 341.56 98.89 4.00 7573.75 462.15 2.48 340.72 98.65 8.00 7507.50 458.11 2.50 339.22 98.21 16.00 5660.00 345.37 2.16 294.52 85.27 Figure 4-6 is a representation of the same information shown in Table 4-5 with one variation. Instead of showing the cumulative displacement results of the concrete cylinder Figures 4-6 and 4-7 represent the volume of th e concrete cylinder according to the location on the cylinder that the data was recorded. Each point along the lines in the chart represents the depth of immersion and volume recorded at that specific location. The format of this data provides a much clearer indication of the area of the shaft that suffered a loss in volume due to deformities caused by the displaced sediment in the shaft. On the charts in Figures 4-6 and 4-7 the area ab ove the curve represents displaced sand that was not pushed out of the drilled shaft as conc rete was placed. A study of the overall shape of the concrete placed shows that the majority of the sediment was disp laced in the first four inches

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49 of the cylinder, reducing the end bearing and side shear surface area of the shaft. Once the sand content of the slurry reached 16% the sand was displaced between 4-18 inches in height on the concrete cylinder. This anomaly was a result of the quantity of sediment and the location of the discharge end of the tremie pipe within an in ch of the base of the cylinder. Under these conditions, the sand was forced into the corners of the cylinder. Once the corners were filled the upward lift on the sand increased unt il the concrete flow found a path of lower resistance around the mass of sand that was inhibiting upward mo vement. These conditions resulted in the majority of the sediment being deposited in the area between four and eigh teen inches of height from the base of the cylinder. Figure 4-7 represents only the fi rst four inches of the concrete test cylinder. This data shows that the volume of the concrete that wa s placed at a 4% sand content did not approach 90% of the expected concrete volume until four inches of concrete was placed in the model shaft. Only the concrete cylinders placed with a 1% sand content achieved 90 % or greater volume of concrete from the initial inch displacement test through 20 inches of displacement. Displacement Results 0% 20% 40% 60% 80% 100% 02468101214161820 Depth of Immersion (inch)Fraction of Total Displacement (%) 1% 2% 4% 8% 16% Figure 4-6. Concrete cylinde r displacement profile

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50 Displacement Results 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 01234 Depth of Immersion (inch)Fraction of Total Displacement (%) 1% 2% 4% 8% 16% Figure 4-7. Displacement profile near the tip of the c oncrete cylinder The photos shown in Figure 4-8 represent th e concrete cylinders that had deformities closest to the average of all the test cylinders cast at each sand content. Deformations become apparent on the surface of the concrete once the sand content percentage of the slurry reaches 4%. These photos clearly show that the sediment that developed on the base of the test cylinders during the two hours allotted for pos sible construction delays between inspector approval of a bottom cleanliness test and the ac tual placement of concrete had a significant affect on the deformation of concrete placed at sand content of 4% and higher.

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51 A B C D E Figure 4-8. Series of photos of cast concrete cylinders. A) 1% sand content, B) 2% sand content, C) 4% sand content, D) 8% sand content, E) 16% sand content.

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52 CHAPTER 5 SUMMARY, CONCLUSIONS AND RECOMENDATIONS 5.1 Summary In spite of the significant am ount of data ga thered on the construction of drilled shafts, there remain significant uncertainties in predicti ng the affects of construction techniques on the field behavior of drilled shafts This research focused specifi cally on the sand content level of slurry used during the excavation of a drilled shaft and the effect that it has on the performance of a drilled shaft. The research procedure was designed to determine whether after two hours heavy sediments suspended in the slurry settled to the shaft bottom, resulting in a loss of shear and bearing capacity of the drille d shaft. In addition, the rese arch incorporated a procedure designed to determine the rate of sedimentati on of a medium to fine sand in slurry. To accomplish these tasks a model drilled shaft was constructed from six inch acrylic pipe in which the concrete could be placed with a model tremie pipe and in which the resulting hardened concrete could be extruded. This procedure represented perfect conditions for the construction of a drilled shaft and yielded a mode l drilled shaft with no significant anomalies. The test was repeated and the placement of concrete occurred after two hours had expired allowing for possible sedimentation of sand suspended in the slurry at sand contents of 1, 2, 4, 8, and 16%. The concrete cylinders were studied and data wa s recorded that showed the change in side shear area as a result of sedimentation and th e effect of sedimentation on the end bearing capacity of the model drilled shaft. The rate of sedimentation could not be recorded directly by means of tracking the buildup of sand along the inside surface of the acrylic cylinder. The author had no available method to directly record the depth of sedimentation because the sediment did not accumulate evenly at the base of the shaft. A uniform sedimentation would have allowed the

PAGE 53

53 depth of sediment to be measured along the insi de surface of the acrylic cylinder. The data on the rate of settlement of medium to fine sands in slurry th at was used to support the conclusions of this research was taken from a study performed at the University of South Florida (Mullins and Ashmway 2005). This information was recorded through an indirect test on the rate of sedimentation that could not eas ily be replicated using the e quipment available during this research. 5.2 Conclusions The sedim entation from the slurry at 4% sa nd content resulted in a loss of area greatest within the first four inches of the shaft tip, or le ss than one times the shaft diameter. This effect shows that the concrete does not displace the se dimentation on the base of the shaft. The commonly held belief that because concrete has a higher unit weight than the soil, it will push the sediment out of the shaft, is not accurate. No te that the unit weight of the slurry with the 4% sand content was 65.5 pcf, or only about 52% of the unit weight of the concrete. The FDOT specifications allow a unit weight less than 75 pcf for the slurry at the time of concrete placement. This research indicates that the 75 pc f may be too high if the slurry unit weight is due to a high sand content. In this experime nt, the lower density slurry caused significant deformities in the concrete due to the restriction of the concrete from conforming to the shape of the acrylic cylinder. These deformities caused signi ficant losses in the end bearing area and side shear capacity. The model tests showed a sand content of 4% set as a maximum by FDOT, results in a loss of almost 3% of the side shear capacity within the bottom diameter. The bearing and structural strength of the shaft n ear the tip will be only about 30% of the theoretical values. This reduction of surface area, bearing area, and structur al strength represents a significant loss for a drilled shaft with 4% slurry sa nd content. The author suspects that the decrease in the load

PAGE 54

54 bearing capacity will be exacerbated as more va riables are introduced to the construction of drilled shafts. Therefore, the reduction in the load bearing capacity of the drilled shaft from slurry with a sand content of 4% is not acceptable. Two hours represents the estimated time require d for construction to transition from the bottom cleanliness inspection to the placement of concrete in a drilled shaft. During this time sedimentation would occur inside of the excav ation. The research shows that these ideal conditions still generate a significant reduction in the load bearing capacity of the drilled shaft, and the safety factor incorporated into the design of the shaft is not nearly as high as previously thought. The required sand content of slurry prio r to concrete placement should be reduced to 1% to ensure that the dr illed shaft is adequately constructed to support the load it is designed for. This research showed that slurry with any sand content higher than 1% resulted in substantial deformities in the concrete. Only the slurry with a 1% sand content resulted in concrete placement that was uniform from the base to the top of the shaft. The tests completed in this research projec t showed that as the concrete is placed, sand accumulates on top of the concrete until a sand content is reached which creates a resistance to the flow of the concrete. When this limiting sa nd content is reached, th e sand moves to the side and the concrete follows the path of least resistance. This creates a neck-in type abnormality in the shaft. One may reason that a deep shaft with 4% sand content may have several abnormalities at various elevations due to this unloading of sand. Figures 4-6 and 4-8 demonstrate this point, especi ally at 16% sand content. 5.3 Recommendations Future research should duplicate this study usi ng Attapulgite. Future research should also include a model reb ar cage because the author su spects that the rebar cage will result in even more severe abnormalities in the shafts. Invest igation of the effects of sand size and slurry

PAGE 55

55 viscosity could be included in future studies. Additional studies could also include longer concrete sections to investigate the sand unloading mechanism during concrete placement. Such studies may show that the allowable sand content should be less for deep shafts than for shallow shafts. The effect of neck-in abnormalities on the integrity of the exposed rebar cage would also provide valuable information about the constructed integrity of the steel when exposed to the corrosive soil conditions found in Florida.

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56 APPENDIX A CONCRETE CYLINDER DATA

PAGE 57

57Table A-1. Sand content control, cylinder #1 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 155 1559.469.463.47 5.455.45159.321.99 0.50 95 2505.8015.263.12 4.899.79128.483.21 0.75 110 3606.7121.973.05 4.8014.39123.344.62 1.00 110 4706.7128.683.02 4.7418.98120.776.04 2.00 350 82021.3650.042.82 17.7335.45105.3610.53 3.00 400 122024.4174.442.81 17.6552.96104.5015.67 4.00 370 159022.5897.022.78 17.4569.82102.1420.42 5.00 390 198023.80120.822.77 17.4287.11101.7625.43 6.00 370 235022.58143.402.76 17.33103.95100.6530.18 7.00 370 272022.58165.972.75 17.26120.8099.8534.93 8.00 390 311023.80189.772.75 17.26138.0999.9039.94 9.00 405 351524.71214.492.75 17.30155.71100.3645.14

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58Table A-2. Sand content control, cylinder #1 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 10.00 310 382518.92233.402.73 17.12171.2298.2949.12 11.00 395 422024.10257.502.73 17.15188.6298.5854.19 12.00 380 460023.19280.692.73 17.14205.6898.5059.07 13.00 390 499023.80304.492.73 17.15222.9798.6464.08 14.00 390 538023.80328.292.73 17.16240.2698.7569.08 15.00 380 576023.19351.482.73 17.16257.3398.6873.96 16.00 375 613522.88374.362.73 17.14274.2898.5378.78 17.00 385 652023.49397.852.73 17.14291.4698.5583.72 18.00 350 687021.36419.212.72 17.10307.8598.0888.22 19.00 375 724522.88442.092.72 17.10324.8197.9993.03 20.00 410 765525.02467.112.73 17.13342.5598.3598.30

PAGE 59

59Table A-3. Sand conten t 1%, cylinder #1 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 115 1157.027.022.99 4.694.69118.201.48 0.50 100 2156.1013.122.89 4.549.08110.502.76 0.75 105 3206.4119.532.88 4.5213.56109.644.11 1.00 85 4055.1924.712.81 4.4017.62104.075.20 2.00 370 77522.5847.292.74 17.2334.4799.579.95 4.00 770 154546.9994.282.74 34.4168.8299.2519.84 6.00 775 232047.29141.572.74 34.43103.2999.3629.79 8.00 765 308546.68188.252.74 34.38137.5399.0939.61 10.00 765 385046.68234.932.74 34.36171.7898.9349.44 12.00 770 462046.99281.912.74 34.36206.1398.9359.33 14.00 750 537045.77327.682.73 34.29240.0498.5768.96 16.00 770 614046.99374.662.73 34.30274.3998.6178.84 18.00 770 691046.99421.652.73 34.31308.7598.6588.73 20.00 775 768547.29468.942.73 34.32343.2298.7498.68

PAGE 60

60Table A-4. Sand conten t 1%, cylinder #2 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 75 754.584.582.41 3.793.7977.090.96 0.50 95 1705.8010.372.57 4.048.0787.372.18 0.75 100 2706.1016.482.64 4.1512.4692.513.47 1.00 90 3605.4921.972.64 4.1516.6192.514.62 2.00 380 74023.1945.152.68 16.8433.6895.089.50 4.00 775 151547.2992.452.71 34.0868.1597.3319.45 6.00 775 229047.29139.742.72 34.21102.6298.0829.41 8.00 765 305546.68186.422.72 34.22136.8698.1339.23 10.00 765 382046.68233.102.72 34.22171.1098.1649.05 12.00 770 459046.99280.082.73 34.24205.4698.2958.94 14.00 770 536046.99327.072.73 34.26239.8298.3868.83 16.00 780 614047.60374.662.73 34.30274.3998.6178.84 18.00 770 691046.99421.652.73 34.31308.7598.6588.73 20.00 760 767046.38468.022.73 34.29342.8898.5598.49

PAGE 61

61Table A-5. Sand conten t 1%, cylinder #3 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 100 1006.106.102.79 4.384.38102.791.28 0.50 90 1905.4911.592.72 4.278.5397.652.44 0.75 100 2906.1017.702.74 4.3012.9199.363.72 1.00 95 3855.8023.492.74 4.2917.1898.934.94 2.00 380 76523.1946.682.73 17.1234.2498.299.82 4.00 760 152546.3893.062.72 34.1968.3797.9719.58 6.00 770 229546.99140.042.73 34.24102.7398.2929.47 8.00 780 307547.60187.642.73 34.33137.3198.7739.49 10.00 760 383546.38234.012.73 34.29171.4498.5549.24 12.00 770 460546.99281.002.73 34.30205.8098.6159.13 14.00 760 536546.38327.372.73 34.28239.9398.4768.89 16.00 770 613546.99374.362.73 34.29274.2898.5378.78 18.00 780 691547.60421.952.73 34.32308.8698.7288.79 20.00 770 768546.99468.942.73 34.32343.2298.7498.68

PAGE 62

62Table A-6. Sand conten t 1%, cylinder #4 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 75 754.584.582.41 3.793.7977.090.96 0.50 90 1655.4910.072.53 3.987.9584.802.12 0.75 90 2555.4915.562.57 4.0412.1187.373.27 1.00 90 3455.4921.052.59 4.0716.2688.654.43 2.00 390 73523.8044.852.67 16.7833.5794.449.44 4.00 780 151547.6092.452.71 34.0868.1597.3319.45 6.00 780 229547.60140.042.73 34.24102.7398.2929.47 8.00 785 308047.90187.942.74 34.36137.4298.9339.55 10.00 790 387048.21236.152.74 34.44172.2299.4549.69 12.00 775 464547.29283.442.74 34.45206.6999.4759.65 14.00 780 542547.60331.032.74 34.47241.2799.5769.66 16.00 770 619546.99378.022.74 34.45275.6299.4979.55 18.00 790 698548.21426.222.75 34.49310.4299.7289.69 20.00 755 774046.07472.292.74 34.44344.4499.4599.39

PAGE 63

63Table A-7. Sand conten t 2%, cylinder #1 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 60 603.663.662.16 3.393.3961.670.77 0.50 95 1555.809.462.45 3.857.7179.661.99 0.75 90 2455.4914.952.52 3.9611.8783.943.15 1.00 95 3405.8020.752.57 4.0416.1487.374.37 2.00 380 72023.1943.932.64 16.6133.2292.519.25 4.00 775 149547.2991.222.70 33.8567.7096.0419.20 6.00 775 227047.29138.522.71 34.06102.1797.2229.15 8.00 770 304046.99185.502.72 34.13136.5397.6539.04 10.00 775 381547.29232.792.72 34.20170.9998.0348.99 12.00 775 459047.29280.082.73 34.24205.4698.2958.94 14.00 770 536046.99327.072.73 34.26239.8298.3868.83 16.00 760 612046.38373.442.73 34.24273.9598.2978.59 18.00 760 688046.38419.822.73 34.23308.0898.2288.35 20.00 770 765046.99466.802.73 34.24342.4398.2998.23

PAGE 64

64Table A-8. Sand conten t 2%, cylinder #2 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 60 603.663.662.16 3.393.3961.670.77 0.50 70 1304.277.932.25 3.537.0666.811.67 0.75 90 2205.4913.422.39 3.7511.2575.382.83 1.00 105 3256.4119.832.51 3.9515.7883.514.17 2.00 380 70523.1943.022.62 16.4432.8790.589.05 4.00 755 146046.0789.092.66 33.4566.9093.7918.75 6.00 770 223046.99136.072.69 33.75101.2695.5128.64 8.00 770 300046.99183.062.70 33.91135.6296.3638.52 10.00 765 376546.68229.742.70 33.97169.8796.7548.35 12.00 775 454047.29277.032.71 34.06204.3497.2258.30 14.00 760 530046.38323.412.71 34.07238.4797.2868.06 16.00 750 605045.77369.172.71 34.05272.3897.1777.69 18.00 775 682547.29416.462.71 34.09306.8497.4387.64 20.00 765 759046.68463.142.72 34.11341.0997.5297.46

PAGE 65

65Table A-9. Sand conten t 2%, cylinder #3 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 40 402.442.441.76 2.772.7741.110.51 0.50 70 1104.276.712.07 3.256.4956.531.41 0.75 75 1854.5811.292.19 3.4410.3163.392.38 1.00 100 2856.1017.392.35 3.6914.7873.243.66 2.00 375 66022.8840.272.53 15.9031.8184.808.48 4.00 755 141546.0786.342.62 32.9365.8690.9018.17 6.00 770 218546.99133.332.66 33.41100.2493.5828.06 8.00 755 294046.07179.402.67 33.57134.2694.4437.75 10.00 760 370046.38225.772.68 33.68168.4095.0847.51 12.00 765 446546.68272.452.69 33.77202.6495.6157.33 14.00 745 521045.46317.912.69 33.78236.4495.6366.90 16.00 770 598046.99364.902.70 33.85270.8096.0476.79 18.00 770 675046.99411.892.70 33.91305.1596.3686.68 20.00 755 750546.07457.962.70 33.92339.1796.4396.37

PAGE 66

66Table A-10. Sand conten t 2%, cylinder #4 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 70 704.274.272.33 3.663.6671.950.90 0.50 75 1454.588.852.37 3.737.4574.521.86 0.75 90 2355.4914.342.47 3.8711.6280.523.02 1.00 90 3255.4919.832.51 3.9515.7883.514.17 2.00 410 73525.0244.852.67 16.7833.5794.449.44 4.00 770 150546.9991.842.70 33.9667.9296.6819.33 6.00 775 228047.29139.132.72 34.13102.3997.6529.28 8.00 775 305547.29186.422.72 34.22136.8698.1339.23 10.00 780 383547.60234.012.73 34.29171.4498.5549.24 12.00 775 461047.29281.302.73 34.32205.9198.7259.20 14.00 750 536045.77327.072.73 34.26239.8298.3868.83 16.00 800 616048.82375.882.74 34.36274.8498.9379.10 18.00 765 692546.68422.562.73 34.34309.0898.8688.92 20.00 775 770047.29469.852.74 34.36343.5598.9398.88

PAGE 67

67Table A-10. Sand conten t 4%, cylinder #1 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 40 402.442.441.76 2.772.7741.110.51 0.50 65 1053.976.412.02 3.176.3453.961.35 0.75 85 1905.1911.592.22 3.4810.4565.102.44 1.00 85 2755.1916.782.31 3.6314.5270.673.53 2.00 375 65022.8839.662.51 15.7831.5683.518.35 4.00 770 142046.9986.652.63 32.9965.9891.2218.23 6.00 750 217045.77132.412.65 33.3099.8992.9427.86 8.00 770 294046.99179.402.67 33.57134.2694.4437.75 10.00 770 371046.99226.382.69 33.72168.6295.3347.64 12.00 745 445545.46271.842.69 33.74202.4295.4057.21 14.00 785 524047.90319.742.70 33.87237.1296.1867.29 16.00 770 601046.99366.732.70 33.93271.4796.5277.17 18.00 770 678046.99413.722.71 33.98305.8396.7987.06 20.00 775 755547.29461.012.71 34.03340.3097.0797.01

PAGE 68

68Table A-11. Sand conten t 4%, cylinder #2 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 25 251.531.531.39 2.192.1925.700.32 0.50 75 1004.586.101.97 3.106.1951.391.28 0.75 90 1905.4911.592.22 3.4810.4565.102.44 1.00 100 2906.1017.702.37 3.7314.9174.523.72 2.00 370 66022.5840.272.53 15.9031.8184.808.48 4.00 765 142546.6886.952.63 33.0566.0991.5418.30 6.00 780 220547.60134.552.67 33.57100.7094.4428.31 8.00 765 297046.68181.232.69 33.74134.9495.4038.14 10.00 780 375047.60228.832.70 33.91169.5396.3648.15 12.00 775 452547.29276.122.71 34.00204.0096.9058.11 14.00 780 530547.60323.712.71 34.08238.5897.3768.12 16.00 770 607546.99370.702.72 34.12272.9497.5778.01 18.00 775 685047.29417.992.72 34.16307.4197.7987.96 20.00 765 761546.68464.672.72 34.16341.6597.8497.78

PAGE 69

69Table A-12. Sand conten t 4%, cylinder #3 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 30 301.831.831.53 2.402.4030.840.39 0.50 65 953.975.801.92 3.026.0348.821.22 0.75 90 1855.4911.292.19 3.4410.3163.392.38 1.00 90 2755.4916.782.31 3.6314.5270.673.53 2.00 365 64022.2739.052.49 15.6631.3282.238.22 4.00 755 139546.0785.122.60 32.7065.4089.6217.91 6.00 775 217047.29132.412.65 33.3099.8992.9427.86 8.00 760 293046.38178.792.67 33.51134.0394.1137.62 10.00 770 370046.99225.772.68 33.68168.4095.0847.51 12.00 755 445546.07271.842.69 33.74202.4295.4057.21 14.00 765 522046.68318.522.69 33.81236.6695.8167.03 16.00 770 599046.99365.512.70 33.88271.0296.2076.92 18.00 760 675046.38411.892.70 33.91305.1596.3686.68 20.00 770 752046.99458.872.70 33.95339.5196.6296.56

PAGE 70

70Table A-13. Sand conten t 4%, cylinder #4 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 20 201.221.221.25 1.961.9620.560.26 0.50 80 1004.886.101.97 3.106.1951.391.28 0.75 85 1855.1911.292.19 3.4410.3163.392.38 1.00 95 2805.8017.092.33 3.6614.6571.953.60 2.00 390 67023.8040.882.55 16.0232.0586.088.60 4.00 760 143046.3887.262.64 33.1166.2191.8718.36 6.00 775 220547.29134.552.67 33.57100.7094.4428.31 8.00 780 298547.60182.142.69 33.82135.2895.8838.33 10.00 770 375546.99229.132.70 33.93169.6496.4948.22 12.00 765 452046.68275.812.71 33.98203.8996.7958.04 14.00 780 530047.60323.412.71 34.07238.4797.2868.06 16.00 770 607046.99370.392.72 34.10272.8397.4977.94 18.00 760 683046.38416.772.72 34.11306.9697.5087.70 20.00 775 760547.29464.062.72 34.14341.4397.7197.66

PAGE 71

71Table A-14. Sand conten t 8%, cylinder #1 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 20 201.221.221.25 1.961.9620.560.26 0.50 60 803.664.881.76 2.775.5441.111.03 0.75 75 1554.589.462.00 3.159.4453.111.99 1.00 90 2455.4914.952.18 3.4313.7062.963.15 2.00 355 60021.6636.612.41 15.1630.3377.097.70 4.00 745 134545.4682.072.56 32.1164.2186.4117.27 6.00 760 210546.38128.452.61 32.8098.3990.1527.03 8.00 755 286046.07174.522.64 33.11132.4291.8736.73 10.00 775 363547.29221.812.66 33.38166.9193.4146.68 12.00 770 440546.99268.792.67 33.55201.2894.3356.56 14.00 760 516546.38315.172.68 33.63235.4194.8066.32 16.00 740 590545.15360.322.68 33.64269.0994.8475.83 18.00 760 666546.38406.702.68 33.69303.2395.1585.58 20.00 765 743046.68453.382.69 33.75337.4795.4695.41

PAGE 72

72Table A-15. Sand conten t 8%, cylinder #2 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 40 402.442.441.76 2.772.7741.110.51 0.50 50 903.055.491.87 2.945.8746.251.16 0.75 80 1704.8810.372.10 3.309.8958.252.18 1.00 55 2253.3613.732.09 3.2813.1357.822.89 2.00 320 54519.5333.262.30 14.4528.9070.027.00 4.00 730 127544.5477.802.49 31.2662.5281.9116.37 6.00 760 203546.38124.182.57 32.2596.7487.1526.13 8.00 770 280546.99171.162.61 32.79131.1490.1036.02 10.00 750 355545.77216.932.63 33.01165.0691.3545.65 12.00 780 433547.60264.522.65 33.28199.6792.8355.67 14.00 780 511547.60312.122.66 33.47234.2793.8865.68 16.00 760 587546.38358.492.67 33.55268.4194.3675.44 18.00 780 665547.60406.092.68 33.67303.0095.0185.46 20.00 770 742546.99453.072.69 33.74337.3695.4095.34

PAGE 73

73Table A-16. Sand conten t 8%, cylinder #3 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 50 503.053.051.97 3.103.1051.390.64 0.50 70 1204.277.322.16 3.396.7861.671.54 0.75 95 2155.8013.122.36 3.7111.1273.662.76 1.00 80 2954.8818.002.39 3.7615.0475.813.79 2.00 385 68023.4941.492.57 16.1432.2887.378.73 4.00 745 142545.4686.952.63 33.0566.0991.5418.30 6.00 760 218546.38133.332.66 33.41100.2493.5828.06 8.00 740 292545.15178.482.67 33.48133.9293.9537.56 10.00 750 367545.77224.252.67 33.57167.8394.4447.19 12.00 740 441545.15269.402.67 33.58201.5194.5456.69 14.00 790 520548.21317.612.69 33.76236.3295.5466.84 16.00 745 595045.46363.072.69 33.76270.1295.5676.40 18.00 760 671046.38409.442.69 33.81304.2595.7986.16 20.00 760 747046.38455.822.69 33.84338.3895.9895.92

PAGE 74

74Table A-17. Sand conten t 8%, cylinder #4 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 60 603.663.662.16 3.393.3961.670.77 0.50 110 1706.7110.372.57 4.048.0787.372.18 0.75 75 2454.5814.952.52 3.9611.8783.943.15 1.00 110 3556.7121.662.63 4.1216.4991.224.56 2.00 370 72522.5844.242.65 16.6733.3493.159.31 4.00 780 150547.6091.842.70 33.9667.9296.6819.33 6.00 760 226546.38138.212.71 34.02102.0697.0129.08 8.00 775 304047.29185.502.72 34.13136.5397.6539.04 10.00 775 381547.29232.792.72 34.20170.9998.0348.99 12.00 780 459547.60280.392.73 34.26205.5798.4059.00 14.00 770 536546.99327.372.73 34.28239.9398.4768.89 16.00 775 614047.29374.662.73 34.30274.3998.6178.84 18.00 780 692047.60422.262.73 34.33308.9798.7988.86 20.00 785 770547.90470.162.74 34.37343.6699.0098.94

PAGE 75

75Table A-18. Sand content 16%, cylinder #1 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 <5 00.000.000.00 0.000.000.000.00 0.50 50 503.053.051.39 2.194.3825.700.64 0.75 80 1304.887.931.84 2.888.6444.541.67 1.00 90 2205.4913.422.07 3.2512.9956.532.83 2.00 350 57021.3634.782.35 14.7829.5673.247.32 3.00 380 95023.1957.972.48 15.5846.7481.3712.20 4.00 350 130021.3679.332.51 15.7863.1383.5116.69 5.00 325 162519.8399.162.51 15.7878.9183.5120.87 6.00 275 190016.78115.942.48 15.5893.4781.3724.40 7.00 250 215015.26131.192.44 15.34107.4078.9327.61 8.00 230 238014.03145.232.40 15.10120.8076.4530.56 9.00 200 258012.20157.432.36 14.82133.4073.6633.13

PAGE 76

76Table A-19. Sand content 16%, cylinder #1 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 10.00 180 276010.98168.422.32 14.54145.4470.9235.44 11.00 170 293010.37178.792.28 14.29157.1768.4537.62 12.00 180 311010.98189.772.24 14.09169.1266.6039.94 13.00 160 32709.76199.542.21 13.88180.5064.6441.99 14.00 190 346011.59211.132.19 13.76192.6863.5144.43 15.00 300 376018.31229.442.21 13.86207.9164.4148.28 16.00 370 413022.58252.012.24 14.07225.0466.3353.03 17.00 385 451523.49275.512.27 14.27242.5468.2557.98 18.00 380 489523.19298.692.30 14.44259.8669.8862.86 19.00 385 528023.49322.192.32 14.59277.2871.4167.80 20.00 370 565022.58344.762.34 14.71294.2972.5972.55

PAGE 77

77Table A-20. Sand content 16%, cylinder #2 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 40 402.442.441.76 2.772.7741.110.51 0.50 70 1104.276.712.07 3.256.4956.531.41 0.75 70 1804.2710.982.16 3.3910.1761.672.31 1.00 80 2604.8815.872.25 3.5314.1266.813.34 2.00 345 60521.0536.922.42 15.2330.4577.737.77 3.00 380 98523.1960.102.53 15.8647.5984.3712.65 4.00 355 134021.6681.772.55 16.0264.0986.0817.21 5.00 340 168020.75102.512.56 16.0580.2486.3421.57 6.00 280 196017.09119.602.52 15.8294.9483.9425.17 7.00 230 219014.03133.632.47 15.48108.3980.3928.12 8.00 225 241513.73147.362.42 15.21121.6877.5731.01 9.00 185 260011.29158.652.37 14.88133.9274.2333.39

PAGE 78

78Table A-21. Sand content 16%, cylinder #2 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 10.00 190 279011.59170.252.33 14.62146.2371.6935.83 11.00 170 296010.37180.622.29 14.36157.9769.1538.01 12.00 180 314010.98191.602.25 14.16169.9467.2440.32 13.00 210 335012.81204.422.24 14.05182.6966.2243.02 14.00 305 365518.61223.032.25 14.15198.0367.0946.93 15.00 370 402522.58245.612.28 14.34215.1168.9551.68 16.00 375 440022.88268.492.31 14.52232.2870.6756.50 17.00 380 478023.19291.682.34 14.68249.5672.2561.38 18.00 385 516523.49315.172.36 14.83266.9373.7466.32 19.00 380 554523.19338.362.38 14.96284.1674.9971.20 20.00 360 590521.97360.322.40 15.04300.8575.8775.83

PAGE 79

79Table A-22. Sand content 16%, cylinder #3 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 <5 00.000.000.00 0.000.000.000.00 0.50 20 201.221.220.88 1.382.7710.280.26 0.75 60 803.664.881.44 2.266.7827.411.03 1.00 70 1504.279.151.71 2.6810.7238.551.93 2.00 340 49020.7529.902.18 13.7027.4162.966.29 3.00 370 86022.5852.482.36 14.8244.4773.6611.04 4.00 330 119020.1472.612.40 15.1060.4076.4515.28 5.00 260 145015.8788.482.37 14.9174.5474.5218.62 6.00 220 167013.42101.902.33 14.6187.6371.5221.44 7.00 210 188012.81114.722.28 14.35100.4369.0124.14 8.00 190 207011.59126.312.24 14.08112.6666.4926.58 9.00 195 226511.90138.212.21 13.89124.9964.6729.08

PAGE 80

80Table A-23. Sand content 16%, cylinder #3 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 10.00 210 247512.81151.022.19 13.77137.7363.6031.78 11.00 200 267512.20163.232.17 13.65150.1762.4934.35 12.00 205 288012.51175.742.16 13.56162.7561.6736.98 13.00 220 310013.42189.162.15 13.52175.7561.2839.81 14.00 310 341018.92208.082.18 13.66191.2862.5943.79 15.00 360 377021.97230.052.21 13.88208.1864.5848.41 16.00 375 414522.88252.932.24 14.09225.4566.5753.23 17.00 360 450521.97274.902.27 14.25242.2768.1057.85 18.00 370 487522.58297.472.29 14.41259.3369.6062.60 19.00 365 524022.27319.742.32 14.54276.2370.8767.29 20.00 350 559021.36341.102.33 14.64292.7271.8271.78

PAGE 81

81Table A-24. Sand content 16%, cylinder #4 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 0.25 45 452.752.751.87 2.942.9446.250.58 0.50 70 1154.277.022.11 3.326.6459.101.48 0.75 60 1753.6610.682.13 3.3410.0359.962.25 1.00 60 2353.6614.342.14 3.3613.4260.393.02 2.00 265 50016.1730.512.20 13.8427.6864.246.42 3.00 210 71012.8143.322.14 13.4740.4060.829.12 4.00 210 92012.8156.142.11 13.2853.1159.1011.81 5.00 190 111011.5967.732.08 13.0465.2257.0514.25 6.00 155 12659.4677.192.02 12.7176.2754.1816.24 7.00 180 144510.9888.172.00 12.5888.0553.0518.56 8.00 160 16059.7697.941.97 12.4099.2051.5520.61 9.00 150 17559.15107.091.95 12.22110.0250.1122.54

PAGE 82

82Table A-25. Sand content 16%, cylinder #4 Immersion depth (inch) Displacement (mL) Cumulative displacement (mL) Displacement (cu. inch) Cumulative displacement (cu. inch) Radius (inch) Surface area (sq. inch) Cumulative surface area (sq. inch) Volume ratio (%) Cumulative volume ratio (%) 10.00 150 19059.15116.241.92 12.08120.8348.9524.46 11.00 190 209511.59127.841.92 12.08132.9048.9426.90 12.00 350 244521.36149.191.99 12.50149.9652.3631.40 13.00 380 282523.19172.382.05 12.91167.7755.8436.28 14.00 385 321023.49195.872.11 13.26185.5958.9241.22 15.00 380 359023.19219.062.16 13.54203.1561.5046.10 16.00 380 397023.19242.252.20 13.79220.6463.7650.98 17.00 380 435023.19265.442.23 14.00238.0765.7555.86 18.00 385 473523.49288.932.26 14.20255.5867.6060.80 19.00 380 511523.19312.122.29 14.36272.9269.1865.68 20.00 380 549523.19335.302.31 14.51290.2270.6070.56

PAGE 83

83 APPENDIX B CONCRETE CYLINDER AREA DATA

PAGE 84

84 Table B-1. Sand content control, cylinder #1 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 0.00 0.000.00 0.00 4.00 2.50 7.242.50 0.72 6.00 2.00 5.794.50 1.30 8.00 0.00 0.004.50 1.30 10.00 0.00 0.004.50 1.30 12.00 0.00 0.004.50 1.30 14.00 0.00 0.004.50 1.30 16.00 0.00 0.004.50 1.30 18.00 0.00 0.004.50 1.30 20.00 0.00 0.004.50 1.30

PAGE 85

85 Table B-2. Sand content 1%, cylinder #1 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 0.50 1.450.50 0.14 4.00 0.00 0.000.50 0.14 6.00 0.00 0.000.50 0.14 8.00 0.00 0.000.50 0.14 10.00 0.00 0.000.50 0.14 12.00 0.00 0.000.50 0.14 14.00 0.00 0.000.50 0.14 16.00 0.00 0.000.50 0.14 18.00 0.00 0.000.50 0.14 20.00 0.00 0.000.50 0.14 Table B-3. Sand content 1%, cylinder #2 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 2.00 5.792.00 0.58 4.00 0.00 0.002.00 0.58 6.00 0.00 0.002.00 0.58 8.00 0.00 0.002.00 0.58 10.00 0.00 0.002.00 0.58 12.00 0.00 0.002.00 0.58 14.00 0.00 0.002.00 0.58 16.00 0.00 0.002.00 0.58 18.00 0.00 0.002.00 0.58 20.00 0.00 0.002.00 0.58

PAGE 86

86 Table B-3. Sand content 1%, cylinder #3 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 5.50 15.925.50 1.59 4.00 0.00 0.005.50 1.59 6.00 0.00 0.005.50 1.59 8.00 0.00 0.005.50 1.59 10.00 0.00 0.005.50 1.59 12.00 0.00 0.005.50 1.59 14.00 0.00 0.005.50 1.59 16.00 0.00 0.005.50 1.59 18.00 0.00 0.005.50 1.59 20.00 0.00 0.005.50 1.59 Table B-4. Sand content 1%, cylinder #4 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 5.50 15.925.50 1.59 4.00 0.00 0.005.50 1.59 6.00 0.00 0.005.50 1.59 8.00 0.00 0.005.50 1.59 10.00 0.00 0.005.50 1.59 12.00 0.00 0.005.50 1.59 14.00 0.00 0.005.50 1.59 16.00 0.00 0.005.50 1.59 18.00 0.00 0.005.50 1.59 20.00 0.00 0.005.50 1.59

PAGE 87

87 Table B-5. Sand content 2%, cylinder #1 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 1.50 4.341.50 0.43 4.00 0.00 0.001.50 0.43 6.00 0.00 0.001.50 0.43 8.00 0.00 0.001.50 0.43 10.00 0.00 0.001.50 0.43 12.00 0.00 0.001.50 0.43 14.00 0.00 0.001.50 0.43 16.00 0.00 0.001.50 0.43 18.00 0.00 0.001.50 0.43 20.00 0.00 0.001.50 0.43 Table B-6. Sand content 2%, cylinder #2 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 1.50 4.341.50 0.43 4.00 0.00 0.001.50 0.43 6.00 0.50 1.452.00 0.58 8.00 0.00 0.002.00 0.58 10.00 0.00 0.002.00 0.58 12.00 0.00 0.002.00 0.58 14.00 0.00 0.002.00 0.58 16.00 0.00 0.002.00 0.58 18.00 0.00 0.002.00 0.58 20.00 0.00 0.002.00 0.58

PAGE 88

88 Table B-7. Sand content 2%, cylinder #3 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 1.00 2.901.00 0.29 4.00 0.00 0.001.00 0.29 6.00 0.00 0.001.00 0.29 8.00 0.00 0.001.00 0.29 10.00 0.00 0.001.00 0.29 12.00 0.00 0.001.00 0.29 14.00 0.00 0.001.00 0.29 16.00 0.50 1.451.50 0.43 18.00 0.00 0.001.50 0.43 20.00 0.00 0.001.50 0.43 Table B-8. Sand content 2%, cylinder #4 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 1.00 2.901.00 0.29 4.00 0.00 0.001.00 0.29 6.00 0.00 0.001.00 0.29 8.00 0.00 0.001.00 0.29 10.00 0.00 0.001.00 0.29 12.00 0.00 0.001.00 0.29 14.00 0.00 0.001.00 0.29 16.00 0.00 0.001.00 0.29 18.00 0.00 0.001.00 0.29 20.00 0.00 0.001.00 0.29

PAGE 89

89 Table B-9. Sand content 4%, cylinder #1 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 10.50 30.4010.50 3.04 4.00 0.50 1.4511.00 3.18 6.00 0.00 0.0011.00 3.18 8.00 0.00 0.0011.00 3.18 10.00 0.00 0.0011.00 3.18 12.00 0.00 0.0011.00 3.18 14.00 0.00 0.0011.00 3.18 16.00 0.00 0.0011.00 3.18 18.00 0.00 0.0011.00 3.18 20.00 0.00 0.0011.00 3.18 Table B-10. Sand conten t 4%, cylinder #2 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 6.00 17.376.00 1.74 4.00 0.00 0.006.00 1.74 6.00 0.00 0.006.00 1.74 8.00 0.00 0.006.00 1.74 10.00 0.00 0.006.00 1.74 12.00 0.00 0.006.00 1.74 14.00 0.00 0.006.00 1.74 16.00 0.00 0.006.00 1.74 18.00 0.00 0.006.00 1.74 20.00 0.00 0.006.00 1.74

PAGE 90

90 Table B-11. Sand conten t 4%, cylinder #3 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 8.50 24.618.50 2.46 4.00 0.50 1.459.00 2.61 6.00 0.00 0.009.00 2.61 8.00 0.00 0.009.00 2.61 10.00 0.00 0.009.00 2.61 12.00 0.00 0.009.00 2.61 14.00 0.00 0.009.00 2.61 16.00 0.00 0.009.00 2.61 18.00 0.00 0.009.00 2.61 20.00 0.00 0.009.00 2.61 Table B-12. Sand conten t 4%, cylinder #4 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 5.00 14.485.00 1.45 4.00 0.00 0.005.00 1.45 6.00 0.00 0.005.00 1.45 8.00 0.00 0.005.00 1.45 10.00 0.00 0.005.00 1.45 12.00 0.00 0.005.00 1.45 14.00 0.00 0.005.00 1.45 16.00 1.50 4.346.50 1.88 18.00 4.00 11.5810.50 3.04 20.00 3.00 8.6913.50 3.91

PAGE 91

91 Table B-13. Sand conten t 8%, cylinder #1 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 7.50 21.717.50 2.17 4.00 4.00 11.5811.50 3.33 6.00 2.00 5.7913.50 3.91 8.00 1.50 4.3415.00 4.34 10.00 1.50 4.3416.50 4.78 12.00 1.50 4.3418.00 5.21 14.00 2.50 7.2420.50 5.94 16.00 4.00 11.5824.50 7.09 18.00 2.00 5.7926.50 7.67 20.00 0.00 0.0026.50 7.67 Table B-14. Sand conten t 8%, cylinder #2 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 11.50 33.2911.50 3.33 4.00 6.00 17.3717.50 5.07 6.00 4.00 11.5821.50 6.22 8.00 1.50 4.3423.00 6.66 10.00 1.00 2.9024.00 6.95 12.00 0.50 1.4524.50 7.09 14.00 0.00 0.0024.50 7.09 16.00 0.00 0.0024.50 7.09 18.00 0.00 0.0024.50 7.09 20.00 0.00 0.0024.50 7.09

PAGE 92

92 Table B-15. Sand conten t 8%, cylinder #3 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 6.00 17.376.00 1.74 4.00 4.00 11.5810.00 2.90 6.00 1.00 2.9011.00 3.18 8.00 3.00 8.6914.00 4.05 10.00 3.50 10.1317.50 5.07 12.00 2.50 7.2420.00 5.79 14.00 1.00 2.9021.00 6.08 16.00 1.00 2.9022.00 6.37 18.00 0.50 1.4522.50 6.51 20.00 0.00 0.0022.50 6.51 Table B-16. Sand conten t 8%, cylinder #4 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 1.50 4.341.50 0.43 4.00 1.50 4.343.00 0.87 6.00 5.00 14.488.00 2.32 8.00 3.50 10.1311.50 3.33 10.00 2.00 5.7913.50 3.91 12.00 0.50 1.4514.00 4.05 14.00 0.00 0.0014.00 4.05 16.00 0.00 0.0014.00 4.05 18.00 0.00 0.0014.00 4.05 20.00 0.00 0.0014.00 4.05

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93 Table B-17. Sand content 16%, cylinder #1 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 23.50 68.0423.50 6.80 4.00 3.50 10.1327.00 7.82 6.00 17.50 50.6744.50 12.88 8.00 25.00 72.3869.50 20.12 10.00 33.50 96.99103.00 29.82 12.00 34.00 98.44137.00 39.66 14.00 34.00 98.44171.00 49.51 16.00 28.50 82.51199.50 57.76 18.00 3.50 10.13203.00 58.77 20.00 4.00 11.58207.00 59.93 Table B-18. Sand content 16%, cylinder #2 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 19.00 55.0119.00 5.50 4.00 15.00 43.4334.00 9.84 6.00 25.00 72.3859.00 17.08 8.00 33.00 95.5492.00 26.64 10.00 34.00 98.44126.00 36.48 12.00 34.00 98.44160.00 46.32 14.00 32.50 94.09192.50 55.73 16.00 7.00 20.27199.50 57.76 18.00 2.50 7.24202.00 58.48 20.00 3.50 10.13205.50 59.50

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94 Table B-19. Sand content 16%, cylinder #3 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 19.00 55.0119.00 5.50 4.00 19.50 56.4638.50 11.15 6.00 27.00 78.1765.50 18.96 8.00 28.00 81.0793.50 27.07 10.00 28.00 81.07121.50 35.18 12.00 29.00 83.96150.50 43.57 14.00 22.50 65.14173.00 50.09 16.00 5.50 15.92178.50 51.68 18.00 4.00 11.58182.50 52.84 20.00 5.00 14.48187.50 54.28 Table B-20. Sand content 16%, cylinder #4 Immersion depth (inch) Area (sq. inch) Side shear area lost (%) Cumulative area (sq. inch) Cumulative side shear area lost (%) 2.00 20.50 59.3520.50 5.94 4.00 18.00 52.1138.50 11.15 6.00 29.00 83.9667.50 19.54 8.00 34.00 98.44101.50 29.39 10.00 34.00 98.44135.50 39.23 12.00 30.50 88.30166.00 48.06 14.00 3.50 10.13169.50 49.07 16.00 4.00 11.58173.50 50.23 18.00 2.00 5.79175.50 50.81 20.00 1.50 4.34177.00 51.24

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95 LIST OF REFERENCES Abdrabbo, F., Abouseeda, H. (2002). Effect of c onstruction procedures on the performance of bored piles. Proceedings, International deep foundations congress, American Society of Civil Engineers, Orlando, Florida. February: 14-16. Camp, W. M., Brown, D. A., Mayne, P. W. (2002) Construction method effects on axial drilled shaft performance. Proceedings, Internat ional Deep Foundations Congress, The GeoInstitute of the American Society of Civil Engi neers, Orlando, Florida, February: 14-16. Chernauskas, L. R., Rhyner, F. C. (2004). Manual for non destructive testing and evaluation of drilled shafts 1st Ed., Deep Foundations Institu te, Hawthorne, New Jersey. Crapps, D. K. (2005). The effects of construc tion time on drilled shaft capacity. Proceedings, Drilled Shaft Construction Effects Semina r, Deep Foundations Institute, Kissimmee, Florida. August 8. Crapps, D. K. (2001). Key points to remember: drilled shaft cleaning & inspections Florida Department of Transportation, Gainesville, Florida. Crapps, D. K. (1986). Design, construction & inspection of dr illed shafts in limerock and limestone. Proceedings, 35th Annual Geotechnical Conference American Society of Civil Engineers /Association of Environmental and Engineering Geologists, Lawrence, Kansas. March 7. Crapps, D. K. (1983). Drilled shaft inspection device saves construction and inspection costs on The Sunshine Skyway Bridge. Proceedings, 42nd Annual Meeting, Southeastern Association of State Highway and Transporta tion Officials, Tarpon Springs, Florida. Crapps, D. K., Schmertmann, J. H. (2002). C ompression top load reaching shaft bottom theory vs. tests. Proceedings, International Deep Foundation Congress, American Society of Civil Engineers, Orlando, Florida. February: 14-16. Dennis, N. D., Castelli, R., O Neill, M. W. (2000). New technological and design developments in deep foundations. Proceedings, Geo-Denve r Conference, American Society of Civil Engineers, Denver, Colorado. August: 5-8. Duncan, J. A. (2002). Geotechnical engineering photo album. Virgina Tech, Blacksburg, Virginia. (August. 8, 2008). Duncan, C. I. (1998). Soils and foundations for architects and engineers 2nd Ed., Norwell, Massachusetts. Federal Highway Administrati on. (2008). Drilled shaft inspector tutorial. United States Department of Transportation, Washington, D.C, Virginia. (August. 8, 2008).

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96 Florida Department of Transportation. (2000). Standard specifications for road and bridge construction Florida Department of Transportation, Tallahassee, Florida. Frizzi, R. P., Meyer, M. E., Zhou, L. (2004). F ull scale field performance of drilled shafts constructed utilizing bentonite and poly mer slurries. Proceedings, Geo-Support Conference, American Society of Civil E ngineers, Orlando, Florid a. January: 29-31. Greenlee, N. T. (2004). Cast in place drilled shafts a state of the art report Howard Needles Tammen and Bergendoff Corporation, Raleigh, North Carolina. Hatch, S. (2000). Practical resear ch answers reallife questions. J. Public Roads 64, no. 3 Turner-Fairbanks Highway Resear ch Center, Mclean, Virginia. (July. 16, 2008). Lambe, William. (1977). Soil testing for engineers John Wiley & Sons, Inc., New York, New York. Mohammad, A. M., Armfield, K. C. (2004). -foot (2.75m) diameter drilled shafts at Cranston viaduct: design, load testing, and construc tion. Proceedings, Geo-Support Conference, American Society of Civil Engineer s, Orlando, Florida. January: 29-31. Mullins, G., Ashmway, A. K. (2005). Factors affecting anomaly form ation in drilled shafts final report University of South Florida, Fl orida Department of Transportation, Tallahassee, Florida. ONeill, M. W. (1999). Some effects of construc tion on the performance of deep foundations. Proceedings, Offshore Research Technology C onference, American Society of Civil Engineers, Austin, Texas. April: 29-30. ONeill, M. W. (1981). Drilled piers and caissons American Society of Civil Engineers, New York, New York. Osterberg, J. (2000). Side shear and end bearing capacity in drilled shafts. Proceedings, GeoDenver Conference, American Society of Civ il Engineers, Denver, Colorado. August: 5-8. Osterberg, J., Hayes, J. (1999). Improvi ng drilled shafts fr om tip to top. J. Foundation Drilling International Association of Foundation Drilling. November: 26-34. Petek, K., Felice, C. W., Holtz, R. D. (2002). Capac ity analysis of drilled shafts with defects. Proceedings, International deep foundations congress, American Society of Civil Engineers, Orlando, Florida. February: 14-16. Reese, L. C., Owens, M., Hoy, H. (1981). Effects of construction methods on drilled shafts. Proceedings, American Society of Civil En gineers National Convention, St. Louis, Missouri. October: 28.

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97 Reese, L. C., Tucker, K. L. (1985). Bentonitic sl urry in constructing drilled piers. Proceedings, Geotechnical Engineering Convention, American Society of Civil Engineers, Denver, Colorado. May: 1. Roesset, J. M. (1999). Analysis, design, c onstruction, and testing of deep foundations. Proceedings, Offshore Research Technology C onference, American Society of Civil Engineers, Austin, Texas. April: 29-30. Schmertmann, J. H., Hayes, J. A., Molnit, T., Osterberg, J. O. (1998). O-cell testing case histories demonstrate the importa nce of bored pile (drilled sh aft) construction technique. Proceedings, Fourth International Conference on Case Histories in Geotechnical Engineering, St. Louis, Missouri, 1103-1115. Turner, J. (2006). Rock-socketed shafts for highway st ructure foundations: a synthesis of highway practice Transportation Research Boar d, Washington D.C., Virginia.

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98 BIOGRAPHICAL SKETCH The venues I have used to gain experience a nd knowledge about dri lled shaft construction have included both academ ic and field experience. I developed an interest in drilled shaft construction techniques during my employment from November 2004 to December 2007 at GPE, Inc. in Gainesville, Fl. In my duties at this company, I served as a technician assembling and repairing the Mini-Sid a purpose built drilled shaft inspection camera that verifies the bottom cleanliness of drilled shafts. During my employment with GPE, Inc. I visited several jobsites in south Florida to perform field repairs to equipmen t and observe the field process of drilled shaft construction. Through GPE, Inc. I was able to attend the ADSC c onference in Orlando, Fl. during 2007 and gain exposure to various dr illed shaft construction implements and technologies. In December 2007, I received my Bachelor of Science in Building Construction degree from the M.E. Rinker School of Building Construction at the University of Fl orida. As a student at the University of Florida, I was required to separately study soil, conc rete, and steel dynamics. I also studied standard constr uction methods for heavy civil c onstruction projects during my internship with The Lane Construction Cor poration from May 2007 to August 2007. While at the University of Florida, I served as captain in November 2007 for the student Heavy Civil Competition held annually in Jacksonville, Florida. During the preparation for this competition I received training on heavy civi l construction techniques by pe rsonnel from Kiewit, Archer Western, and Nelson Construction.