JKR WEAP Energy Formula Teh

Engineering Study Program 090700 – 29000 Year 2004 Dynamic Pile Testing Using Pile Driving Analyzer (PDA) – Phase II

Research Report No. 1

Title:

Driveability Study of Long Spun Pile using Energy Formulas, Wave Equation Analysis and Pile Driving Monitoring

Site:

Route 6 Extension Works, Bulatan Bayan Lepas, Pulau Pinang

Dated:

23rd Septmeber 2004

Client:

Jabatan Kerja Raya Malaysia Cawangan Pakar & Kejuruteraan Awam & Kumpulan Ikram Sdn Bhd Ikram Research Centre Sdn Bhd

UNOFFICIAL COPY

Prepared by:

Project Director 1:

Project Director 2:

……………………

………………………………..

…………………….

Teh Kim Ong T Testing Agency

Dr HM Abd. Aziz B. KM Hanifah JKR

Ir Mohd Nor B. Omar JKR

Research Report No. 1 Driveability Study of Long Spun Pile using Energy Formulas, Wave Equation Analysis and Pile Driving Monitoring Date: 23rd September 2004

Prepared for:

Jabatan Kerja Raya Cawangan Kejuruteraan & Pakar & Kumpulan IKRAM Sdn Bhd IKRAM Research Centre Sdn Bhd

Engineering Study Program Year 2004, Phase II – Research Report No. 1

page

Table of Contents

0.

Abstract

…1

1.

Introduction

…2

2.

Energy Formulas

…3

3.

Wave Equation Analysis

…4

4.

Details of Project and Subsoil

…6

5.

Analysis by Energy Formulas

…8

6.

Analysis by WEAP

…9

7.

Pile Driving Monitoring

..11

8.

Blow Count Matching Technique

..13

9.

Effects of Temporary Interruption

10.

Conclusions

16 ..18

Figure 1

Pile and Soil Model in WEAP

..20

Figure 2

Boreholes Adjacent to Test Pile Group No. 1.

..21

Figure 3

Layout of Test Pile Group No. 1.

..22

Figure 4

WEAP Results of Predictive Case for TP1.

..23

Figure 5

Pile Driving Monitoring results for TP1.

..24

Figure 6a~e

Predicted versus Measured Driving Quantities for TP1.

..25

Figure 7a~e

Refined versus Measured Driving Quantities for TP1.

..25

Table 1

Installation Details of Test Pile Group No. 1.

..30

Table 2

Assessment Using Energy Formulas.

..31

Table 3

Parameters Used In Predictive WEAP Analysis.

..32

Table 4

Comparison Between Predicted and Measured Quantities at End-of-Drive. ..33

Table 5

Effects of Temporary Interruption.

..34

Appendix A

Comparison of Measured and Predicted Driving Quantities.

..35

Using Blow Count Matching Method for TP1 to TP9.

~62

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Engineering Study Program Year 2004, Phase II – Research Report No. 1

DRIVEABILITY STUDY OF LONG SPUN PILE USING ENERGY FORMULAS, WAVE EQUATION ANALYSIS AND PILE DRIVING MONITORING

Abstract: For decades, many engineers are impressed by the capability of wave equation analysis in assessing driveability of piles. However, routine application of such analysis has yet to prevail while on the other hand improper use of the classical ‘energy’ or ‘dynamic formulas’ seems to becoming a concern. This paper presents a project involved installation of long and large diameter spun pile through marine alluvium soils where both energy formulas and wave equation analysis program (WEAP) were employed and compared to illustrate shortcomings and strengths of the different methods. The predicted driving stresses and final set of the wave equation analyses appeared to compare reasonably to the actual measurements from pile driving monitoring (PDM). A blow count matching method using WEAP and the piling records is introduced to refine the predictive WEAP models and produce site-specific typical design parameters. The applicability of the method is reviewed by comparing the computed driving quantities to those of the actual measurements. Observation in the pile driving monitoring revealed significant impacts of temporary interruption in piling works to the driveability of pile.

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Engineering Study Program Year 2004, Phase II – Research Report No. 1

1. Introduction Since it introduction in decades ago, many engineers have been amazed by the long soughtafter rationale solution offered by the wave equation analysis in assessing driveability of piles in various complex contexts. However, few are applying such analysis as routine practice while many are employing the classical ‘energy formulas’ for determining hammer system and driving criterion for piling projects. The strength and shortcoming of the two methods are illustrated through a piling works involving 600mm diameter prestressed concrete spun piles driven in excess of 50m in alluvium deposits with dynamic measurements using Pile Driving Analyzer (PDA) throughout installation of piles. The predictions of the two different types of analysis are compared against the actual measurements to verify their applicability.

Subsequently a refinement procedure for the WEAP analysis is introduced and reviewed whereby the measured blow count record is used as the reference while the predictive model of the WEAP analysis is iteratively adjusted until the computed blow count plot matches the measured one. The applicability of this method is reviewed by comparing the results of other driving quantities, i.e. capacity, transferred energy and driving stresses, produced by the refined predictive model to those measured by the PDA.

Finally, the adverse effects of temporary interruption in piling to the driveability and the induced driving stresses are highlighted based on observations made in the pile driving monitoring.

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Engineering Study Program Year 2004, Phase II – Research Report No. 1

2. Energy Formulas Energy formulas are basically derived from the Newton’s law of impact by considering energy conservation, i.e. energy delivered by hammer equals to work done for permanently penetrating a pile into soil plus energy lost in the pile, soil and driving system (cumulative term for hammer cushion, helmet and pile cushion). As work done to penetrate a pile essentially equals to the product of driving resistance/pile capacity, Ru, and permanent set, s, the above concept can be briefly written as:

Eh = Ru.s + E’p + E’s +E’d

or rearranged to related Ru to s,

Ru= (Eh – E’p – E’s – E’d)/s

where Eh is the energy of the hammer immediately preceding an impact, E’p, E’s and E’d are energies lost in the pile, soil and driving system respectively upon impact.

The differences in the various available energy formulas mainly lie on the different assumptions made in quantifying the energy losses in the complex dynamic mechanisms. Often, these formulas are over-simplified and lack of proper considerations to adequately cover important aspects like dynamic soil damping, transient mode of stresswave propagation, effects of driving system, performance of diesel hammer, complex soil profile etc. In fact it may be more rightful to consider the term Ru to mean the driving resistance, which consists of static and dynamic components, than ‘static’ pile capacity.

As a result, applicability of such formulas may be an issue for cases like long pile (adequate consideration of the transient nature of the stresswave become important), composite piles, and complex driving system and soil profile.

In summary, as the energy formulas are of semi-empirical nature, it should be use with caution and only when extensive experience on the local site and piling system are available. It should always be verified and empirically “calibrated” by pile load testing with proper attentions given to variables like different pile length, spatial variation of subsoil etc in the calibration. page 3

Engineering Study Program Year 2004, Phase II – Research Report No. 1

3. Wave Equation Analysis

Far back in 1943, Terzaghi made an insightful remark: " In spite of their obvious deficiencies and their unreliability the pile formulas still enjoy a great popularity among practicing engineers, because the use of these formulas reduced the design of pile foundations to a very simple procedure. The price one pays for this artificial simplification is very high…..In order to obtain reliable information concerning the effect of the impact of the hammer on the penetration of the piles, it is necessary to take into consideration the vibrations which are produced by the impact".

Vibrations, in this context, mean stress waves of transient of nature, and mechanisms involving dynamic motions and properties of the pile, soil and hammer system of concerned.

EAL Smith in early 1950's introduced the wave equation concept which was later expanded and developed into wave equation analysis programs (WEAP) available for PC in late 1980's. In general, WEAP idealized the pile and hammer systems into discrete lump masses with springs, and the soils into springs with sliders and dashpots as shown in Figure 1.

A hammer impact would induce external force and motion to the upper boundary of an elastic pile. In consideration of the initial/boundary conditions of the discrete segments and the equilibrium of forces and motions, the variations of force and displacement along the pile could be determined for each time-interval considered.

When analyzed for an adequate duration of time, the analysis may then produce full time traces of force and displacement for each segment of pile under each hammer impact. Engineer may gather useful information from these results, for instance, final displacement of pile-top upon impact (i.e. set) for the given soil resistance/parameters, the maximum driving stresses induced in the pile due to the adopted hammer and energy transmitted to the pile by the hammer (i.e. hammer performance).

As WEAP gives a rational analysis for an impact event, it is a good tool for Engineer to perform parametric study on the various driving parameters e.g. stiffness of cushion, pile and soil, hammer weight, drop height, pile length, soil resistance and its profile, which would enable a better understanding on the piling mechanism and subsequently promote logical and proper solutions to problems relating to piling works. This is essential as piling works have page 4

Engineering Study Program Year 2004, Phase II – Research Report No. 1

becoming more and more challenging nowadays when structures become heavier, taller, longer and site conditions become more complex where large and long piles have to be driven through landfills, hard layers and deep waters. In contrast, energy formulas were developed based on experience and empirical studies on deep foundations of much smaller scale decades ago, they may not be adequate or applicable for use in nowadays’ projects without extensive correlation study and adjustment on the semi-empirical formulas.

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Engineering Study Program Year 2004, Phase II – Research Report No. 1

4. Details of Project and Subsoil The project is an extension to a proposed viaduct along an existing highway at Penang Island, Malaysia. The early phase of the viaduct adopted large diameter bored and cast in-situ concrete pile of 1.2 and 1.8m diameter, mostly socketed into hard rock, as the foundation system. In consideration of the significant potential cost and time saving, 600mm diameter x 100mm thick open-ended prestressed concrete spun pile is proposed for the extension section.

The subsoils of the site consisted of thick soft to dense marine alluvia of Quartenary deposits overlying granitic rock, which was encountered at a depth of typically beyond 50m. The borelogs of two rotary wash boring holes adjacent to the pile group of concerned namely test pile group no. 1 is given in Figure 2.

Test pile group no. 1 consisted of nine numbers of preliminary test piles namely ref. TP1 to TP9 whiched were planned to be installed to various depths and set conditions as outlined in Table 1. The layout of the test pile group no. 1 is presented in Figure 3.

The specification requested a long term pile capacity of 430tons and it is considered that the pile should be driven to achieve an end-of-drive (EOD) capacity of similar order to allow for the potential relaxation of the founding saturated dense silt-sand materials which may to certain extent offset the set-up effect along the pile shaft. This would require the pile to be driven to the dense sand/silt layer at a depth of exceeding 50m. Due to site space constraint and availability, the biggest piling rig proposed was a 10 tons single acting hydraulic hammer made Twinwood with an operative drop height of maximum 1000mm.

In view of the above, two main concerns arose namely whether the 10-ton hydraulic hammer could safely drive the long heavy pile to the required capacity and what would be the impacts of the induced vibrations and ground displacements.

The concern on the derivability issue was studied using energy formulas and WEAP. The WEAP suggested that the derivability was not an issue for the given pile-soil-hammer configuration.

To adequately investigate the various issues concerning the piling works, an extensive testing and monitoring program was planned and carried out for the installation of test pile group no. page 6

Engineering Study Program Year 2004, Phase II – Research Report No. 1

1. The program consisted of pile driving monitoring throughout piling and dynamic load testing at various elapse time upon piling, and monitoring of ambient air, noise, vibration and ground displacement. The following sections discussed the issue of driveability in detail while the environmental, vibration and ground displacement monitoring are beyond the scope of this report.

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Engineering Study Program Year 2004, Phase II – Research Report No. 1

5. Analysis By Energy Formulas Assessments by energy formulas are presented herein for comparison purposes only to the WEAP analysis.

Three formulas namely Hiley's, Danish's and Janbu's are adopted to

calculate the maximum set corresponding to the EOD capacity of 403.5 ton (based on the maximum design pile length of 57m and the static capacity calculation with reference to borehole no. RB-P04, being the borehole with more complex profile) using the 10-ton hydraulic hammer, or to calculate the minimum hammer weight required if the 10-ton weight is inadequate. The calculation and results are summarized in Table 2.

Note that the dynamic elastic modulus Ed, is used in the calculation.

For a concrete

characteristic cube strength, fcu, of 78.5 kPa, British Standard BS 8110: Part 2: 1985: Section Seven suggested an averaged Ed of 43.76 x 106 kPa. The elastic compression of pile used in the Hiley's Formulas is computed by assuming a linear load distribution with total shaft and toe resistance of 158.8 and 244.7tons respectively. The assumed drop height is 1000mm.

Based on the three energy formulas, a 10-ton hydraulic drop hammer is far from adequate to install the pile for the required capacity. For a practical value of set of 3.0mm/blow (i.e. 30mm/10 blows), the minimum weights of hammer required are 17, 35 and 16 tons respectively for Hileys, Danish's and Janbu's Formulas. The range of the results seems s to be fairly large.

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Engineering Study Program Year 2004, Phase II – Research Report No. 1

6. Analysis by WEAP The objectives of the WEAP analysis are to determine the driveability of the pile through the given soils using the proposed hammer without inducing excessive compressive and driving tensile stresses detrimentally to the pile. For the purposes of assessment of driveability, compressive stress and downward travelling tensile stress as a result of reflection of the upward compressive stress at pile-top in a hard driving condition, an optimistic set of soil resistance parameters were chosen in order to produce a conservative prediction.

As such, the unit shaft and toe resistance of sand were estimated based on Meyerhof’s (1956) recommendations namely 2N and 400N (kN/m2) respectively where N is the count of Standard Penetration Test. For fines, the adhesions were estimated using alpha method with adhesion factor based on Tomlinson’s (1986) works and cohesion values, Cu, of 4N and 6N for silt and clay respectively. Unit toe resistance for silt and clay were estimated as 270N and 9Cu respectively. For parameters of driving system/hammer, the details compiled in the hammer data file of GRLWEAP for JUNTTAN HHK10 were used as the proposed hammer made was not in the list. The other input parameters like soil quakes, soil damping factor, etc were essentially based on the appropriate typical values recommended by the program. The parameters chosen for the predictive WEAP analysis are summarized in Table 3.

The results as plotted by the program are presented in Figure 4. Based on the plot of blow count over depth, the driveability of the pile is not an issue and the blow count at the end of driving is 456blow/m equivalent to a set of 2.2mm/blow for the EOD capacity of 403.5tons. The maximum axial compressive driving stress was 25.6Mpa which was well within the limit of 0.85fcu –fpe (= 59.4Mpa) as recommended by Federal Highway Administration, USA where fpe is the effective prestress. The maximum axial tensile driving stress was 4.9Mpa which was also well within the limit of fpe + 0.25(fcu)0.5 (=9 .5Mpa) as recommended by the same organization.

A full analysis may require a second run with pessimistic soil resistance parameters for conservative prediction of the tensile driving stress as soft driving conditions induce tensile reflection at the pile toe. However, while driveability is not an issue for the above case, the second run is considered not necessary because if high tensile stress is observed during the pile driving monitoring, the hammer drop height could be appropriately reduced to control the stress during soft driving. page 9

Engineering Study Program Year 2004, Phase II – Research Report No. 1

Obviously the two different methods of analysis have resulted in two extremely different conclusions. Energy formulas suggested that the 10-ton hammer was far from adequate for the required capacity and a larger hammer of 16 to 35tons may instead required while the WEAP analysis indicated that the 10-ton hammer would be adequate even for a set of rather optimistic soil resistance parameters.

In light of the WEAP analysis results, the site was ready for actual piling with dynamic measurements to be taken near pile-top by PDA throughout the installation.

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Engineering Study Program Year 2004, Phase II – Research Report No. 1

7. Pile Driving Monitoring Pile driving monitoring were carried out throughout the installation of all the nine test piles ref. TP1 to TP9. Being the first and longest pile driven in the group, pile ref. TP1 is discussed in detail in the following texts.

TP1 was monitored using PDA during piling except for the first 5m penetration where the pile was advanced under hammer weight. The pile was set and terminated at a penetration depth of 53.3m and the monitoring results are graphically presented in Figure 5.

These plots of result of TP1 could not be directly compared to those of the WEAP analysis because the actual drop heights adopted were different from those analyzed except probably for below 30m where the drop heights ranged from 0.5 to 0.7m (0.8m at final set) in the actual case and 0.6 to 0.8m in the analyzed predictive case. Keeping in view of the difference in the drop height, the predicted and measured results for penetration below 30m are compared in Figures 6a through e.

Comparing the two sets of plot, the static pile capacity through depth was obviously overpredicted (as partly intended) resulting in the harder driving effort indicated by the higher blow count plot in the predicted case. In anticipation of the set-up effects occurred during splicing, the drop height was reduced from 0.7 to 0.5m when resumed piling from 41.5 to 44.0m to reduce the driving stresses and ground vibrations. Although the compressive stress decreased correspondingly, the tensile stress and static pile capacity still registered an obvious increase. This has indicated the potential significant impact from temporary interruption during piling to the integrity of the pile and would be further reviewed in the subsequent discussions. Nevertheless, such effects of temporary interruption are again for conservative reason over-predicted in the predictive case, resulting in significantly higher stresses and blow count.

Bearing in mind the difference in the actual and assumed drop heights, the predicted maximum energy transferred (EMX) and compressive driving stress (CSX) at various depths were considered to compare reasonably well to those of the measured. The predicted maximum tensile driving stress (TSX) is normally sensitive to the adopted value of the toe resistance because tensile stress is induced from reflection at free/soft ends. In this case, the predicted TSX appeared to be somewhat lower at a depth below 42m compared to the page 11

Engineering Study Program Year 2004, Phase II – Research Report No. 1

measured values, likely attributable to the high toe resistance assumed in the analysis for the sand-silt layers.

It is more meaningful to compare the end-of-driving conditions as in this case same drop height was adopted and the predicted and measured pile capacities were similar. For a more accurate comparison, the results of CAPWAP analysis of a representative dynamic data captured during EOD were used. As presented in Table 4, at drop height of 0.8m, the predicted EOD pile capacity and set were 403.5tons and 2.2mm/blow respectively compared to the measured 373tons and 2.1mm/blow respectively. The error was 8 and 5% respectively for the capacity and set. As for TSX and CSX, the predicted and measured values at EOD were 1.9 and 2.2Mpa, and 22.7 and 24.6MPa respectively. The comparisons are considered good with insignificant magnitude of error.

However, with a predicted and measured value of 5.12 and 6.65tm respectively, the error in the EMX prediction was higher.

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Engineering Study Program Year 2004, Phase II – Research Report No. 1

8. Blow Count Matching Technique It was attempted to match the predicted blow count to the measured one by iteratively adjusting the analysis parameters of the WEAP model. Once a reasonable match between the two plots are obtained, the final model is thought to be reasonably represent the site/works conditions as it produces similar driving resistance in term of blow count in a wave equation analysis.

The applicability of this technique could be reviewed by comparing the computed driving quantities namely Ru, EMX, CSX and TSX using the final refined model to those measured in the PDM. If proven to be applicable, this matching technique together with WEAP analysis (in this case GRLWEAP is used) would be a useful mean to turn the simple piling records which is usually abundantly available into valuable typical design parameters and information pertaining to the specific site. On the other hand, this technique also represents a more rational way to analyze the piling records than a visual inspection, and would produce a site-specific model for further needs of analysis like change of hammer, pile type and size etc.

Reviewing the comparison between the predicted and measured plots as presented in Figures 6, several observations and possible adjustments are as follow: (a)

The static soil resistance are obviously over-predicted (partly intended) for the purpose of driveability study. The over-prediction is thought to attributable to toe resistance for two reasons: the predicted and measured EOD shaft resistance was similar, and the predicted internal soil plug of 39m was significantly longer than the measured length of 22m at EOD. Also, for conservative reason, it is optimistically assumed that there was no lost of toe resistance during the process of driving, and that the unit toe resistance were 400N and 270N (kN/m2; N is the SPT value) for the sand and silt respectively. Judging from the measured plots, the loss factor was adjusted to 0.6 (50% different compared to 0.4 used for the shaft as loss in shaft resistance due to piling is often thought to be more severe than for toe due to various reasons). Subsequently the toe resistance was further arbitrarily adjusted in an iterative manner until the computed blow counts over depth matches with the actual measurement.

(b)

Hammer drop height adjusted to the observed/actual height.

(c)

Pile termination length adjusted to the actual length of 53.3m with some adjustment on soil resistance from below 50.0m to match the observed EOD pile capacity. page 13

Engineering Study Program Year 2004, Phase II – Research Report No. 1

(d)

The set-up effect due to the temporary interrupt of piling was grossly over-predicted. Set-up time and “relative energy” are adjusted to 10days and about 2m respectively.

The WEAP analysis was re-run with the above adjustments and other parameters being essentially unchanged, i.e. following the recommendations given the GRLWEAP manual. The results of the final analysis using the refined model of TP1 are plotted and compared to the measured results in Figure 7a through e.

The plots of blow count of the revised analysis and actual measurement after the matching procedures are practically identical with certain localized deviation at about 27m (i.e. joint location) likely due to the difficulty in modeling the set-up effects accurately.Comparing Figures 6b and 7b, the correlation between the predicted and measured Ru appeared to have been greatly improved by the matching procedures and the correlation as indicated in Figure 7b is considered reasonably good. It is of interest to note that relatively larger deviation is observed between a depth of about 30 to 43m where the borelog indicated sand layer sandwiched by silt layers.

In a similar trend, the CSX and EMX plots both indicated substantial improvement after the blow count matching procedures and illustrated a good correlation between the refined analysis and actual measurement.

However, the results are not so straightforward for the case of TSX. After the blow count matching procedures, the computed TSX appeared to have been greatly improved between a depth of 43m to pile toe, but deteriorated between a depth of about 30 to 43m (were the sandwiched sand layer was!). The reason for such an observation is thought to be attributable to inaccurately assumed toe resistance as the matching technique at this stage may not be able to uniquely and accurately separate the toe and shaft resistance components while such separation is essential for accurate determination of the induced tensile stress.

The remaining eight piles namely ref. TP2 to 8 were also analyzed using the same matching technique and the results are plotted and compared to those of the PDM in Appendix A. Similar observations as for the case of pile ref. TP1 could be made for these eight cases where correlation are reasonable for Ru, EMX and CSX and less certain for TSX.

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Engineering Study Program Year 2004, Phase II – Research Report No. 1

In conclusion, the technique of blow count matching using WEAP analysis described above may produce enhanced and reasonable prediction for various driving quantities especially Ru, EMX and CSX. It can be a mean to refine the design parameters used in the preliminary analysis for further analysis when variations arises in the same site (e.g. a change of hammer, different pile size/type etc) or for application in other sites with similar site/work conditions.

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Engineering Study Program Year 2004, Phase II – Research Report No. 1

9. Effects of Temporary Interruption It is often observed on site that the driving resistance changed when resumed piling after a temporary pause of the piling works due to splicing or lunch break. The change could be an increase in the apparent driving resistance or reverse depending on various factors like set-up of clayey soils, relaxation of saturated silts or fine sands, re-establishment of soil grip that lost due to flexing of pile etc. The effects of the temporary interruption obviously have no place in the energy formulas but could be rationally modeled in the WEAP. However, relatively little concern and recommendation regarding this factor is expressed in the literatures. While the impact of temporary pause may be significant to the driveability and integrity of the piles, it may not seem obvious in many occasions because it is a temporary issue and the damage induced on the pile may manifest into disaster only in the subsequently prolonged/hard driving. It is also not easy to justify the impacts of this factor as pile driving monitoring are not commonly done for all piling project.

In this preliminary test pile program, the result plots of pile driving monitoring as presented in Figure 5 have clearly revealed that the driveability and driving stresses could changed significantly on the adverse side after a temporary pause for splicing. All the monitoring results of the nine piles in test pile group no. 1 are reviewed for such effects by comparing averaged of last five readings of Ru and TSX prior to the pause to the subsequent first ten readings (ten excessive hammer blows are enough to damage a pile). The results of such review involving fifteen events and interruption duration that ranged from 1hr 4min to 3hr 3min (except one event of 16hr 24min) are summarized in Table 5.

In general, all the reviewed events of temporary pause have resulted obvious increases in the quantities of Ru and TSX when resumed piling after the pause, except for one event for each quantity.

The ratios of Ru after pause to those before pause ranged from 1.10 to 2.77 for fourteen events and 0.85 for the remaining one exceptional event. As for TSX, the values ranged from 0.00 to 1.91MPa prior to the pause to a range of 0.81 to 3.99MPa after the pause for fourteen events and from 0.92 to 0.81MPa for the remaining one exceptional event.

Although such increases in Ru and TSX are not considered an issue for this project, the impacts may be felt very differently in projects with adverse soil conditions or under-weight page 16

Engineering Study Program Year 2004, Phase II – Research Report No. 1

hammer as the increase ratio of 1.10 to 2.77 in Ru may then pose a severe problem in the induced driving stresses and pile integrity. To avoid such potential problem, the effects of temporary interruption should be adequately considered during design stage using proper analysis tool like WEAP.

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Engineering Study Program Year 2004, Phase II – Research Report No. 1

10. Conclusions Driveability analyses using energy formulas and WEAP, and pile driving monitoring using PDA were performed for a preliminary test pile program involving installation of nine numbers of 600mm diameter open-ended prestressed concrete spun piles through marine alluvium deposits using a 10-ton single acting hydraulic hammer.

The energy formulas and the WEAP produced two extremes in the driveability assessment. The former required a hammer of 16 to 35tons to drive the pile to the targeted EOD capacity of 403.5tons at 3mm/blow and 1m drop while the latter indicated the applicability of the 10ton hammer for the same job at only 0.8m drop without having issue of excessive driving stresses. A reviewing on its fundamental revealed that energy formulas are essentially oversimplified solutions for the complex mechanism of pile driving hence have limited application. Wave equation analysis, on the other hand, provides a rational approach to study the interactions of the complex pile-soil-hammer system, promote insightful understanding and solutions to the challenging piling works.

The successful installation of test pile ref. TP1 confirmed the reasonable solution of the wave equation analysis. For the given targeted driving resistance at the final pile penetration, WAEP analysis produced accurate predictions to the pile set, CSX, TSX and EMX compared to those measured in the PDM.

It is also demonstrated that, using the measured blow count plot as reference, the analysis parameters could be refined to produce a match between the predicted and measured blow count plots. When a reasonable match between the two plots is achieved, the predicted plots of other driving quantities especially Ru, CSX and EMX also compared reasonably well with the measured plots.

This blow count matching technique may be employed to produce site-specific typical design parameters for further needs of analysis, e.g. change of hammer/pile size/pile type or for study of other sites with similar formation. Further, the refined pile-soil model obtained through the analysis may be adopted in a static analysis to produce a prediction of the pile load-settlement curve for comparison to the static load test results. In other words, the technique turns the simple and abundantly available piling records into valuable typical design parameters and information pertaining to the specific site. On the other hand, it also page 18

Engineering Study Program Year 2004, Phase II – Research Report No. 1

represents a more rational way to analyze the piling records than a visual inspection. The technique could be further enhanced by calibration to the results of static pile load test.

Finally, the results of the pile driving monitoring have indicated significant effects of temporary interruption of the piling works to the driving resistance and stresses. The static driving resistance was observed to change predominantly at a factor ranged from 1.10 to 2.77 for a interruption duration ranged from 1hr 4min to 3hr 3min (except for one case 16hr 24min). The maximum tensile driving stress was observed to change predominantly from a range of 0.00 to 1.91MPa to 0.81 to 3.99MPa. It is recommended to adequately consider the effects of temporary interruption in the driveability assessment of piles using WEAP to avoid potential problems associated with excessive driving resistance and stresses.

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Engineering Study Program Year 2004, Phase II – Research Report No. 1

Figure 1: Pile and Soil Models in WEAP.

Pile Schematic

WEAP Pile Model

Smith Soil Model – Static & Dynamic

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Engineering Study Program Year 2004, Phase II – Research Report No. 1

Figure 2: Boreholes Adjacent to Test Piles Group No. 1.

SPT-

Test Pile Group 1

P40 RB-PO4 CH 11167

N

N 4

3m

7

6

4.5m

8

6 8

10

6.0m

7

12

16

9

12

11

15

12

14

14

19

14

23

13

13

8

12

10

14

11

9m

14

12

25.5m

11

15

12

14

16

13

17

17

17

8

15

10

13

18

19

12

8

11

15

14

12

16

15

18

16

21

15

20

16

22

48m

21

24

22

25

23

23

20

23

54.0m

0%

R/r = 59%

20

0%

R/r = 27%

17

0%

R/r = 100%

0%

R/r = 50%

30

58.0m

72%

R/r = 63%

31%

R/r = 91%

81%

R/r = 100%

95%

R/r = 95%

63%

R/r = 100%

100%

R/r = 100%

98%

R/r = 100%

95%

R/r = 100%

67%

R/r = 100%

100%

R/r = 100% EOB = 68.0m GWL 81.13m

CLAY

SPT-

6

10

Legend: SAND

P39 RB-PO3 CH 11210

EOB = 62.0m GWL 2.527m

43m

FRACTURED GRANITE FRESH GRANITE

SILT

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Engineering Study Program Year 2004, Phase II – Research Report No. 1

Figure 3: Layout of Test Pile Group No. 1

P39

House

to Georgetown

7.5m

Right Side

2.5m 2.5m

3.0m

(0m) A2 N3 TP1 TP3 V1 5.0m

9.0m

TP4

TP6

6.5m

drain TP7

House

TP9

9m Internal Road

P40

Grass / Buffer Zone Site boundary

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Left Side

7.0m

to Bayan Lepas

6.0m

11.0m

House monsoon drain

Engineering Study Program Year 2004, Phase II – Research Report No. 1

Figure 4: WEAP Results of Predictive Case for TP1.

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Engineering Study Program Year 2004, Phase II – Research Report No. 1

Figure 5: Results of Pile Driving Monitoring for TP1.

page 24

Engineering Study Program Year 2004, Phase II – Research Report No. 1

Figure 6a: Predicted vs Measured Blow Count for TP1 30

35

Depth (m)

40

45

Predicted Blow Count

50

Measured Blow Count

55

60 0

100

200

300

400

500

600

700

800

900

1000

Blow Count (blow/m)

Figure 7a: Measured Blow Count vs Adjusted Blow Count for TP1 30

35

Reasonable match is achieved 40 Depth (m)

Measured Blow Count Adjusted Blow Count

45

50

55 0

100

200

300

400

500

600

Blow Count (blow/m)

page 25

700

800

900

1000

Engineering Study Program Year 2004, Phase II – Research Report No. 1

Figure 6b: Predicted vs Measured Static Capacity 30

Higher resistance is conservatively adopted.

35

Depth (m)

40

45 Predicted Measured

50

55

60 0

100

200

300 RU (ton)

400

500

600

Figure 7b: Measured vs Refined Static Capacity for TP1 30

35

Depth (m)

40

Measured

45

Refined

Correlation improved

50

55 0

100

200

300 RU (ton)

page 26

400

500

600

Engineering Study Program Year 2004, Phase II – Research Report No. 1

Figure 6c: Predicted TSX vs Measured TSX for TP1 30

35

Depth (m)

40

Predicted TSX

45

Measured TSX 50

55

60

0

5

10

15

20

TSX (MPa)

Figure 7c: Measured TSX vs Refined TSX for TP1 30

35

40 Depth (m)

Correlation improved for lower depth but deteriorated for upper depth

Measured TSX Refined TSX

45

50

55 0

5

10 TSX (MPa)

15

page 27

20

Engineering Study Program Year 2004, Phase II – Research Report No. 1

Figure 6d: Predicted CSX vs Measured CSX for TP1 30

35

Depth (m)

40

Predicted CSX

45

Measured CSX 50

55

60

0

5

10

15

20

25

30

CSX (MPa)

Figure 7d: Measured CSX vs Refined CSX for TP1 30

Correlation greatly improved 35

Depth (m)

40 Measured CSX Refined CSX

45

50

55 0

5

10

15 CSX (MPa)

page 28

20

25

30

Engineering Study Program Year 2004, Phase II – Research Report No. 1

Figure 6e: Predicted EMX vs Measured EMXfor TP1 30

35

Depth (m)

40

Predicted EMX

45

Measured EMX 50

55

60

0

5

10

15

20

EMX (ton.m)

Figure 7e: Measured EMX vs Refined EMX for TP1 30

35

Correlation greatly improved Depth (m)

40 Measured EMX Refined EMX

45

50

55 0

5

10 EMX (ton.m)

15

page 29

20

Engineering Study Program Year 2004, Phase II – Research Report No. 1

Table 1: Details of Pile Installation. Pile Ref.

Installation Details

Prebore Depth (m)

Soil Plug (m)

Total Blow (no.)

TP1

• • • •

57m=12+15+15+15m. set at 2.1mm/blow @ 53.2m. with pipe shoe. new 100mm plywood pile cushion used.

•

2m

•

22.0

2755

TP2

• • • •

57m=12+15+15+15m. set at 1.0mm/blow @ 52.8m. with pipe shoe. one round welding using 5mm rod at 3rd joint.

•

4m

•

25.0

2572

TP3

• • •

54m=12+12+15+15m. set at 0.9mm/blow @ 52.3m. with pipe shoe.

•

6m

•

21.7

2861

TP4

• • •

48m=12+12+12+12m unset at 12.0mm/blow @ 46.5m. with pipe shoe.

•

2m

•

17.0

1362

TP5

• • • •

48m=12+12+12+12m unset @ 46.5m. with pipe shoe. resumed piling after first two segments left overnight.

•

2m

•

17.7

1654

TP6

• • • •

48m=12+12+12+12m. unset @ 46.5m. with pipe shoe. resumed piling after 1st three segments left overnight.

•

2m

•

19.6

2321

TP7

• • • •

•

2m

•

18.2

2263

TP8

• • •

45m=15+15+15m. unset @ 43.8m. without shoe. changed 100mm plywood pile cushion after 39.5m. 45m=15+15+15m. unset @ 44.3m. without shoe.

•

1m

•

23.6

2091

•

15.8

2018

TP9

• • • •

45m=15+15+15m. unset @ 43.5m. without shoe. resumed piling after first segment left overnight.

page 30

(excavated)

•

1m

(excavated)

Engineering Study Program Year 2004, Phase II – Research Report No. 1

Table 2 : Driveability Assessment using Energy Formulas Calculation/Description

Set (mm/blow) For Ru=403.5 t, 10 t hammer x 1m drop

Hammer (ton) For Ru=403.5 t, S = 3mm/b & 1m drop

- 6.2 mm/blow, Indicative of inadequate hammer

17 tons

-16.5 mm/blow, Indicative of inadequate hammer

35 tons

inadequate hammer

16 tons

The Formulas and typical values of parameters are Referred to Poulos and Davis (1980) 1) Hiley's Formulae Ru =

ef. W.H S + 1/2 (C1+C2+C3)

x

Where, ef = hammer efficiency

W t n2.Wp W + Wp

= 0.85

C1 = temporary compression for hammer & pile cushion = 0.2" + 0.3" = 12.70mm (for very hard driving at stress of 14,000 kPa). C2 = temporary compression of pile (considered a linear shaft resistance of 158.8 t and a toe resistance of 244.7 t) = 26.87 mm C3 = temporary compression of ground/quake = 2.54mm N = coefficient of restitution = 0.25 for single acting hammer with timber cushion for hammer and pile Wp = pile weight = 23.3 tons W

= hammer weight

2) Danish's Formulae Ru = L

ef. W. H. . S + (2.ef. WHL/A.Ep) 1/2

= pile length = 57 m,

Ep = elastic modulus of pile = Ed = 43.76 x 106 kPa A = pile sectional area = 0.1571 m2 3) Janbu's Formulae Ru =

1 Ku

W.H S

,

Ku = Cd (1+ (1+ ηe/Cd) 1/2) Cd = 0.75 + 0.15 Wp = 1.1 W ηe =

W.H.L A.Ep.S2

= 92.1253 for S = 3mm/blow & H = 1.0m drop

∴ Ku = 11.2289 Ru = 296.7 ton < 403.5 ton, NG.

page 31

Engineering Study Program Year 2004, Phase II – Research Report No. 1

Table 3 : Parameters used in Predictive WEAP Analysis No

Desriptions

Remarks

1.

Damping (s/m)

2.

Quake (mm)

3.

Set-up time (hr) : 1.0 (the time required for full heal/gain)

Estimate

Relative energy (m) : 0.5 (approximately the distance of penetration that would cause full lost of the set-up effect)

Estimate

4.

Resistance loss factor : Shaft =0.4 Toe = 1.0

Estimate

5.

a) Elastic modulus of plywood = 210,000kPa

Shaft : 0.16 for sand 0.65 for fines Toe : 0.50 for all soils Shaft : 2.5mm for all normal sizes Toe : full diameter / 120 for hard driving

Typical value of GRLWEAP

Typical value of GRLWEAP

b) Thickness of plywood pile cushion = 75mm c) Thickness of plywood hammer cushion = 75mm d) C.O.R. = 0.5 6.

a) Unit Shaft Resistance (kPa), fs : Sand = 2N Silt = α (4N) Clay = α (6N)

Meyerhof (1956) α by Tomlinson (1986) α by Tomlinson (1986)

b) Unit Toe Resistance (kPa), ft : Sand = 400N Silt = 270N Clay = 9Cu

Meyerhof (1956) Estimated Typical value

c) Unit shaft resistance of plug in internal shaft: Assumed similar to external shaft

Assumed

Note : For toe resistance, use the lesser of (internal shaft resistance + ft x nett toe area) and (ft x gross toe area).

7.

Pile made = 12m starter + 15m + 15m + 15m = 57m

Spliced by welding

8.

Drop height = 0.2 to 0.4m for 1st & 2nd segments = 0.6m for 3rd segment = 0.8m for 4th segment

-

page 32

Engineering Study Program Year 2004, Phase II – Research Report No. 1

Table 4: Comparison between Predicted and Measured Quantities at End-of-Drive Parameter

Predicted Value

Measured Value

(GRLWEAP results)

(CAPWAP results)

Static Pile Capacity

Total = 403.5

Total = 373.0

(ton)

Shaft = 158.8

Shaft = 170.0

Toe = 244.7

Toe = 203.0

Final set (mm/blow)

2.2

2.1

Compressive Driving

22.7

24.6

1.9

2.2

5.12

6.65

Stress (MPa)

Tensile Driving Stress (MPa)

Maximum Transferred Energy (t.m)

page 33

Engineering Study Program Year 2004, Phase II – Research Report No. 1

Table 5: Effects of Temporary Interruption. Joint TP Ref. TP1

Location

Waiting Time

Average Ru

Average TSX

Before (5) After (10) Ratio After/before Before (5) After (10)

Ratio

12m

2hr 22min

85

72

0.85

0

1.550

-

27m

1hr 35min

64

108

1.69

0.040

3.302

82.55

42m

1hr 13min

111

161

1.45

1.928

3.919

2.03

12m

1hr 24min

67

82

1.22

0.100

2.541

25.41

27m

3hr 3min

82

127

1.55

0.165

2.967

17.98

42m

1hr 4min

176

222

1.26

1.917

2.159

1.13

12m

1hr 11min

67

74

1.10

0.101

2.727

27.00

24m

1hr 8min

74

205

2.77

0.888

3.369

3.79

39m

1hr 25min

171

210

1.23

0.921

0.812

0.88

TP4

36m

1hr 9 min

167

223

1.34

1.506

3.993

2.65

TP5

36m

2hr 21min

159

260

1.64

2.96

3.647

1.23

TP6

36m

16hr 24min

176

315

1.79

0.917

2.832

3.09

TP7

30m

1hr 30min

129

176

1.36

0.191

2.045

1.07

TP8

30m

1hr 11min

110

153

1.39

0.372

2.547

6.85

TP9

30m

1hr 40min

139

224

1.61

1.909

3.006

1.57

TP2

TP3

notes:

(1) Before (5) means 5 readings prior to the interrupt (2) After (10) means the first 10 readings after resumed piling. (3) Ru = static driving resistance, TSX = maximum axial tensile driving stress, TP=test pile. RSU = CASE Method of capcity prediction - unloading case RMX = CASE Method of capacity prediction - maximum solution

page 34

Engineering Study Program Year 2004, Phase II – Research Report No. 1

Appendix A Comparison of Measured and Predicted Driving Quantities Using Blow Count Matching Method for TP1 to TP9.

page 35

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF BLOW COUNT FOR TP1

Computed Blow Count vs Measured Blow Count 10

15

20

Depth (m)

25

30

35

Computed Blow Count

40

Measured Blow Count

45

50

55 0

100

200

300

Blow Count (blow/m)

page 36

400

500

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CAPACITY AND ENERGY FOR TP1 Predicted Capacity vs Measured Capacity 10

15

20

30 Predicted Capacity Measured Capacity

35

40

45

50

55 0

50

100

150

200

250 RU (ton)

300

350

400

450

500

Predicted EMX vs Measured EMX 10

15

20

25

Depth (m)

Depth (m)

25

30 Predicted EMX

35

Measured EMX

40

45

50

55

0

5

10 EMX (ton.m)

page 37

15

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CSX AND TSX FOR TP1

Predicted CSX vs Measured CSX 10

15

20

30 Predicted CSX

35

Measured CSX

40

45

50

55

0

5

10

15

20

25

30

CSX (MPa)

Predicted TSX vs Measured TSX 10

15

20

25

Depth (m)

Depth (m)

25

30

Predicted TSX

35

Measured TSX

40

45

50

55

0

5 TSX (MPa)

page 38

10

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF BLOW COUNT FOR TP2

Computed Blow Count vs Measured Blow Count 10

15

20

Depth (m)

25

30

35

Computed Blow Count

40

Measured Blow Count

45

50

55 0

100

200

300

400

500

600

Blow Count (blow/m)

page 39

700

800

900

1000

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CAPACITY AND ENERGY FOR TP2 Predicted Capacity vs Measured Capacity 10

15

20

30 Predicted Ru

35

Measured Ru

40

45

50

55 0

50

100

150

200

250 Ru (ton)

300

350

400

450

500

Predicted EMX vs Measured EMX 10

15

20

25

Depth (m)

Depth (m)

25

30 Predicted EMX Measured EMX

35

40

45

50

55

0

5

10 EMX (ton.m)

page 40

15

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CSX AND TSX FOR TP2

Predicted CSX vs Measured CSX 10

15

20

30 Predicted CSX

35

Measured CSX

40

45

50

55 0

10

20

30

40

50

CSX (MPa)

Predicted TSX vs Measured TSX 10

15

20

25

Depth (m)

Depth (m)

25

30 Predicted TSX

35

Measured TSX

40

45

50

55

0

5

10 TSX (MPa)

page 41

15

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF BLOW COUNT FOR TP3

Computed Blow Count vs Measured Blow Count 10

15

20

Depth (m)

25

30

35

Computed Blow Count

40

Measured Blow Count

45

50

55 0

100

200

300

Blow Count (blow/m)

page 42

400

500

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CAPACITY AND EMX FOR TP3

Predicted Capacity vs Measured Capacity 10

15

20

30

Predicted Ru

35

Measured Ru

40

45

50

55 0

50

100

150

200

250 Ru (ton)

300

350

400

450

500

Predicted EMX vs Measured EMX 10

15

20

25

Depth (m)

Depth (m)

25

30 Predicted EMX Measured EMX

35

40

45

50

55

0

5

10 EMX (ton.m)

page 43

15

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CSX AND TSX FOR TP3

Predicted CSX vs Measured CSX 10

15

20

Depth (m)

25

30 Predicted CSX

35

Measured CSX

40

45

50

55

0

5

10

15

20

25

30

35

40

CSX (MPa)

Predicted TSX vs Measured TSX 10

15

20

Depth (m)

25

30 Predicted TSX Measured TSX

35

40

45

50

55

0

5 TSX (MPa)

page 44

10

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF BLOW COUNT FOR TP4

Computed Blow Count vs Measured Blow Count 20

25

Depth (m)

30

35 Computed Blow Count

40

Measured Blow Count

45

50 0

50

100

Blow Count (blow/m)

page 45

150

200

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CAPACITY AND EMX FOR TP4

Predicted Capacity vs Measured Capacity 20

25

Depth (m)

30

Predicted Capacity

35

Measured Capacity

40

45

50 0

50

100

150

200

250 Ru (ton)

300

350

400

450

500

Predicted EMX vs Measured EMX 20

25

Depth (m)

30 Predicted EMX

35

Measured EMX

40

45

50 0

5

10 EMX (ton.m)

page 46

15

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CSX AND TSX FOR TP4

Predicted CSX vs Measured CSX 20

25

Depth (m)

30

Predicted CSX

35

Measured CSX

40

45

50

0

5

10

15

20

25

30

35

40

CSX (MPa)

Predicted TSX vs Measured TSX 20

25

Depth (m)

30

Predicted TSX

35

Measured TSX

40

45

50

0

5 TSX (MPa)

page 47

10

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF BLOW COUNT FOR TP5

Computed Blow Count vs Measured Blow Count 20

25

Depth (m)

30

35 Computed Blow Count

40

Measured Blow Count

45

50 0

100

200

Blow Count (blow/m)

page 48

300

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CAPACITY AND EMX FOR TP5

Predicted Capacity vs Measured Capacity 20

25

Predicted Capacity

35

Measured Capacity

40

45

50 0

50

100

150

200

250 Ru (ton)

300

350

400

450

500

Predicted EMX vs Measured EMX 20

25

30

Depth (m)

Depth (m)

30

Predicted EMX

35 Measured EMX

40

45

50

0

5

10 EMX (ton.m)

page 49

15

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CSX AND TSX FOR TP5

Predicted CSX vs Measured CSX 20

25

Depth (m)

30

Predicted CSX

35

Measured CSX

40

45

50

0

5

10

15

20

25

30

35

40

CSX (MPa)

Predicted TSX vs Actual TSX 20

25

Depth (m)

30

Predicted TSX

35

Measured TSX

40

45

50 0

5 TSX (MPa)

page 50

10

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF BLOW COUNT FOR TP6

Computed Blow Count vs Measured Blow Count 20

25

Depth (m)

30

35 Computed Blow Count

40

Measured Blow Count

45

50 0

100

200

Blow Count (blow/m)

page 51

300

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CAPACITY AND EMX FOR TP6

Predicted Capacity vs Measured Capacity 20

25

Predicted Capacity

35

Measured Capacity

40

45

50 0

50

100

150

200

250 Ru (ton)

300

350

400

450

500

Predicted EMX vs Measured EMX 20

25

30

Depth (m)

Depth (m)

30

Predicted EMX

35 Measured EMX

40

45

50

0

5

10 EMX (ton.m)

page 52

15

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CSX AND TSX FOR TP6

Predicted CSX vs Measured CSX 20

25

Depth (m)

30

Predicted CSX

35

Measured CSX

40

45

50

0

5

10

15

20

25

30

35

40

CSX (MPa)

Predicted TSX vs Measured TSX 20

25

Depth (m)

30

Predicted TSX

35

Measured TSX

40

45

50 0

5 TSX (MPa)

page 53

10

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF BLOW COUNT FOR TP7

Computed Blow Count vs Measured Blow Count 10

15

20

Depth (m)

25

30 Computed Blow Count

35 Measured Blow Count

40

45

50 0

100

200

Blow Count (blow/m)

page 54

300

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CAPACITY AND EMX FOR TP7

Predicted Capacity vs Measured Capacity 10

15

20

30

Predicted Capacity

35

Measured Capacity

40

45

50 0

50

100

150

200

250 Ru (ton)

300

350

400

450

500

Predicted EMX vs Actual EMX 10

15

20

25 Depth (m)

Depth (m)

25

Predicted EMX

30 Measured EMX

35

40

45

50

0

5

10 EMX (ton.m)

page 55

15

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CSX AND TSX FOR TP7

Predicted CSX vs Measured CSX 10

15

20

Depth (m)

25

Predicted CSX

30

Measured CSX

35

40

45

50

0

5

10

15

20

25

30

35

40

CSX (MPa)

Predicted TSX vs Measured TSX 10

15

20

Depth (m)

25 Predicted TSX

30

Measured TSX

35

40

45

50 0

5 TSX (MPa)

page 56

10

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF BLOW COUNT FOR TP8

Computed Blow Count vs Measured Blow Count 10

15

20

Depth (m)

25

30 Computed Blow Count

35 Measured Blow Count

40

45

50 0

100

200

Blow Count (blow/m)

page 57

300

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CAPACITY AND EMX FOR TP8

Predicted Capacity vs Measured Capacity 10

15

20

30

Predicted Capacity

35

Measured Capacity

40

45

50 0

50

100

150

200

250 Ru (ton)

300

350

400

450

500

Predicted EMX vs Measured EMX 10

15

20

25 Depth (m)

Depth (m)

25

Predicted EMX

30 Measured EMX

35

40

45

50

0

5

10 EMX (ton.m)

page 58

15

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CSX AND TSX FOR TP8

Predicted CSX vs Measured CSX 10

15

20

Depth (m)

25

Predicted CSX

30

Measured CSX

35

40

45

50

0

5

10

15

20

25

30

35

40

CSX (MPa)

Predicted TSX vs Measured TSX 10

15

20

Depth (m)

25 Predicted TSX

30

Measured TSX

35

40

45

50 0

5 TSX (MPa)

page 59

10

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF BLOW COUNT FOR TP9

Computed Blow Count vs Measured Blow Count 10

15

20

Depth (m)

25

30 Computed Blow Count

35 Measured Blow Count

40

45

50 0

100

200

Blow Count (blow/m)

page 60

300

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CAPACITY AND EMX FOR TP9

Predicted Capacity vs Measured Capacity 10

15

20

30

Predicted Capacity

35

Measured Capacity

40

45

50 0

50

100

150

200

250 Ru (ton)

300

350

400

450

500

Predicted EMX vs Measured EMX 10

15

20

25 Depth (m)

Depth (m)

25

Predicted EMX

30 Measured EMX

35

40

45

50

0

5

10 EMX (ton.m)

page 61

15

Engineering Study Program Year 2004, Phase II – Research Report No. 1

COMPARISON OF CSX AND TSX FOR TP9

Predicted CSX vs Measured CSX 10

15

20

Depth (m)

25

Predicted CSX

30

Measured CSX

35

40

45

50

0

5

10

15

20

25

30

35

40

CSX (MPa)

Predicted TSX vs Measured TSX 10

15

20

Depth (m)

25 Predicted TSX

30

Measured TSX

35

40

45

50 0

5 TSX (MPa)

page 62

10