bdslt method statement _bt maung.pdf

BIDIRECTIONAL STATIC LOAD TEST MENAIKTARAF JALAN NEGERI (P10) DARI BATU MAUNG KE JALAN SULTAN AZLAN SHAH, PULAU PINANG Method Statement (TP 1) Date : 9 June 2015 Version : V1R0M0 Prepared by:

Strainstall Malaysia Sdn Bhd (200894-H) 19, Jalan TPP 1/10 Taman Industri Puchong 47160 Puchong Selangor Darul Ehsan, MALAYSIA

Bidirectional Static Load Test Method Statement Batu Maung

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Table of Content

1.0 OVERVIEW ......................................................................................................................... 3 2.0 INSTALLATION ................................................................................................................. 3 3.0 HYDRAULIC JACK POSITIONING ............................................................................... 4 4.0 INSTRUMENTATION ........................................................................................................ 5 5.0 TEST PROCEDURE ........................................................................................................... 5 6.0 MEASUREMENTS .............................................................................................................. 6 7.0 REPORTING OF TEST RESULTS ................................................................................... 6 8.0 QUALITY ASSURANCE .................................................................................................... 7 9.0 GUIDE TO POST-TEST GROUTING .............................................................................. 8 APPENDICES Appendix A - Instrumentation Schematic Showing the Pile Layout for a Bidirectional

Static Load Test Figure 1 - Schematic Diagram of Bored Pile Layout

Figure 2 - Schematic Diagram of Annular Void Grouting Figure 3 - Schematic Diagram of Jack Grouting

Figure 4 - Layout of Hydraulic Jack Assembly Appendix B - Calculation of Hydraulic Jack Level Appendix C - Loading Schedule of Test pile Appendix D - Schematic Diagram of Testing Procedure Appendix E - Construction of Equivalent Top-Loaded Load Settlement Curve Appendix F - Sample Plots from a Typical Test Appendix G - BDSLT Risk Assessment Appendix H - Contractor Worksheet


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1.0 OVERVIEW

This method statement is aimed at describing a single-level bidirectional static load test that has been proposed for one (1) number of working bored pile at the MENAIKTARAF JALAN NEGERI (P10) DARI BATU MAUNG KE JALAN SULTAN AZLAN SHAH, PULAU PINANG project. Test pile description is summarized as follows:

Pile No.

Pile Size

(mm) Working

Load (tonne)

Test Load

(tonne) Pile Length

(m) Jack

Assembly TP1 800 350 700 43.0 2x200T

The proposed test is executed using single-level configuration (comprising one level of hydraulic jack assembly) to enable the top-loading equivalent load-settlement profile to be computed. Using a single-level configuration, the pile will be divided into two segments. The hydraulic jack assembly will contain bi-directional hydraulic jacks in a symmetrical formation. The hydraulic jack assembly delivers 400 tonne loading in both the upward and downward directions, resulting in a total capacity of 800 tonne. A schematic section of the test pile is included in Appendix A.

2.0 INSTALLATION

Bored pile excavation will proceed under the piling contractors work plan as approved by the Engineer. Upon reaching the final toe elevation, the pile bottom will be cleaned and approved by the Engineer for concrete placement. The hydraulic jack assembly, related hydraulic supply, and instrumentation will be lowered into the hole attached to the steel cage. Hydraulic jack assembly inside the cage will be supported either using angle bar welded to the cage or directly welded to the cage. The steel cage will be fabricated in a number of pieces (depending on the pile length) and spliced together over the bored hole. The number of cages should be kept to a minimum to speed up the installation process. The first section of the reinforcing cage containing the hydraulic jack assembly will be lowered into the bored hole and temporarily supported on the steel casing. The second cage section will then be lowered vertically into position and spliced to the top of the first cage.

After the entire reinforcing cage has been lowered into the shaft, the cage may be supported on the steel casing during concrete placement. Alternatively, the cage can be fabricated in a single piece, but the final arrangement must be coordinated with Strainstall Malaysia Sdn. Bhd. personnel. Concrete placement will commence utilizing suitable size tremie pipe of sufficient length so as to extend beyond the hydraulic jack assembly to the pile toe. Cutouts of sufficient sizes will be provided in the hydraulic jack steel bearing plates to accommodate the tremie pipe.


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A funnel will also be constructed between the opening in the top plate of the hydraulic jack assembly and the main vertical rebar to guide the concrete tremie pipe through the steel bearing plates. The funnel also serves as a means of preventing the tremie pipe from accidentally hitting the hydraulic fittings on the top of jack by forming a physical barrier apart from serving as a guide.

Further protecting to the hydraulic hoses is in the form of foam shields and protection bars leading from the hydraulic fittings to the cell top the cage vertical rebars which protect the hoses from the effects of flowing concrete. Alternative concreting methods may be used but must be coordinated beforehand with Strainstall Malaysia Sdn. Bhd. personnel.

Temporary support will be welded between top and bottom bearing plates. This is to allow the holding of weight below the bottom bearing plate once the reinforcing cage is cut off at the bottom bearing plate level.

The concrete mix should allow for minimum slump between 175 25mm and should contain sufficient retarder to maintain workability for a minimum of 3 hours is preferred. The concrete will be placed up to the designed cut-off level as per standard / approved concreting procedures. The Contractor Worksheet is included in Appendix H.

3.0 HYDRAULIC JACK POSITIONING

Positioning of hydraulic jack assembly is determined based on soil data. This is used as the basis to compute the expected skin friction and end-bearing capacities of the pile. Strainstall Malaysia Sdn. Bhd. will normally present the optimum position of the hydraulic jack assembly in the pile for the Engineers approval. The main aim of positioning the assembly will be to equalize the bi-directional forces in the pile so that failure in one direction does not occur prematurely. The detailed positioning requirements are calculated based on the Engineers pile design and the soil conditions as shown by the borehole records.

It must be stressed that all calculation are based on empirical formulae which does not imply that they are fail-proof but at the time represents the most prudent and accurate positioning based on available information and knowledge. By the acceptance of this method statement, the Engineer is deemed to have reviewed the computations as contained herein and is agreeable to the recommendation for the jack location.

The position of the hydraulic jack assembly for pile no. TP1 is recommended at 17.0m from the pile toe level. The pile design calculation is included in Appendix B.


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4.0 INSTRUMENTATION Hydraulic jacks All hydraulic jacks will be calibrated individually prior to sending to the site. Measurement of movements For measurement of the movement of the bearing plates, tell-tale extensometers with displacement transducers of maximum 100 mm stroke will be used. Measurement of jack pressure A high-pressure bourdon gauge and calibrated electronic pressure transducer capable of taking pressure reading up to 15,000 PSI will be used to monitor the hydraulic jack pressure, from which the loading is derived by applying the calibration factor of the hydraulic jack to the pressure.

5.0 TEST PROCEDURE

The bi-directional static load test will be carried out when the concrete strength of the pile is adequate to sustain the maximum required test load. During the commencement of the test, all hydraulic jacks forming part of the assembly will have the welded seal break off during the process of load applying. The hydraulic jack will be internally pressurized using a common hydraulic system (which ensures uniform and synchronised pressurization of both hydraulic jacks), creating an upward force on the shaft in upper friction and an equal, but downward force in combined lower shaft friction and/or end bearing. As mentioned, the hydraulic jack load is determined by relating the applied hydraulic pressure to load calibration. A high-range calibrated pressure transducer will be used to read the pressure on the pump line. Schematic diagram of testing procedure is included in Appendix D. The load will be removed and testing considers finished when one of the following conditions prevail before the load cycle(s) complete:

1. The test pile reaches its ultimate capacity in either the upward or downward direction

(when either one of the upward or downward displacement exceeds the limit set by the Engineer or 10% of the pile diameter, whichever is lesser);

2. The hydraulic jack reaches its maximum loading capacity;

3. The maximum travel of the jack is reached. The nominal stroke for each of the

hydraulic jack used in these test is nominally 180 mm.

Load-settlement readings will be automatically recorded at 1-minute interval. The loading will be carried out in stages as shown in Appendix C.


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6.0 MEASUREMENTS

The downward expansion of each of the hydraulic jack assembly is measured directly by using two (2) nos. displacement transducers attached to tell tale extensometers that are anchored against the bottom bearing plate of the hydraulic jack assembly at equidistant. The upward vertical movement of the top of the hydraulic jack assembly is measured using two (2) nos. displacement transducers attached to tell-tale extensometers that are anchored to the top bearing plate of the hydraulic jack assembly at equidistant. Pile compression above hydraulic jack assembly will be measured directly at the top of the shaft using two (2) nos. displacement transducers and/or non-encased telltale rods attached to the pile top at equidistant. Pile compression below hydraulic jack assembly will be measured using two (2) nos. displacement transducers and non-encased telltale rods installed at the pile bottom at equidistant. The movement of the pile is closely monitored and the displacement transducers are adjusted if the movements exceed 100 mm. This is in keeping with the normal practise in maintained load tests where pile movements exceed the range of the displacement measurement instruments. The displacement and pressure transducers are connected to data logger or equivalent equipment. The data logger is, in turn, connected to a laptop computer. This arrangement allows the reading of displacement and pressure to be recorded and stored automatically during the test. All measurements are made with reference to a reference frame constructed at platform level. Precise level will be used to monitor any possible deflection for the constructed reference beam during testing.

7.0 REPORTING OF TEST RESULTS

Upon completion of the test, the client will be issued with a preliminary report that shows the load-settlement curves for the test. A sample of the load-settlement charts provided in a typical report is included in Appendix F. A final test report to be endorsed by a Professional Engineer will be issued within a pre-determined time frame, in accordance with the contract allowing for review of the report by the clients Engineers.

The write-up on Construction of Equivalent Top-Loaded Settlement Curve is included in Appendix E.


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8.0 QUALITY ASSURANCE

The hydraulic jacks have been tested and calibrated to a specific capacity individually and then welded in the closed position prior to shipment. The hydraulic hose assembly will be tested to 10,000 PSI prior to installation to ensure a leak-free system. All displacement transducers are calibrated individually by the respective manufacturers (and/or accredited calibration laboratory) prior to shipment, to ensure specified accuracy and functionality.

The on-site inspection and checking of the hydraulic jack assembly includes, but is not limited to the following:

1. The fabrication of the hydraulic jack assembly is supervised and the perpendicular

attachment to the main vertical rebar is supervised and checked to be within acceptable tolerance;

2. The tack welds holding the hydraulic jack assembly in the closed position are visually checked prior to lifting and installation into the shaft;

3. SSM personnel will work with the contractor to plan the hoisting and lifting of the reinforcement cage from horizontal to vertical, paying specific attention to prevent potential deflection of the reinforcing cage from exceeding the acceptable tolerance;

4. Immediately prior to lowering the reinforcement cage into the shaft, it is again checked to be within the acceptable tolerance. If this criterion is not met upon inspection, corrective adjustments or corrective procedures will be suggested to bring the assembly within the acceptable tolerance;

5. Placement of tremie pipe and concrete is observed, in order to minimize the potential for damage and improper seating. It must be noted however that the Contractor is responsible for the overall successful completion of the concreting process which includes the following: checking and ensuring that concrete of the required specifications is used, and ensuring that the appropriate tremie pipe and concreting equipment are used.

The BDSLT Risk Assessment analysis included in Appendix G summarizes the overall risks associated with performing the specified BDSLT test. In order to minimize potential problems arising from damage to electronic equipments during installation, there are several built-in redundancies in the embedded measurement system:

The expansion of the hydraulic jacks will be monitored using a minimum of four (4)

nos. displacement transducers in conjunction with extensometers; any one of which would provide adequate measurement should the other fail. If all were to fail, telltale rods can be inserted into pre-installed grout pipes and/or pressure relief pipes (if these are installed), which would enable mechanical measurements of the downward movement of the bottom bearing plates.

The automated recording of all measurements allows for storage of the recorded data on the data logger, on the laptop computer and other storage devices. Furthermore, manual readings and notes are taken during the test as a backup. If any of the automated equipment fails, backup manual readout devices will be on site and can be used.


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All external measurement devices (above ground devices) used in measuring the pile

head movement, telltale movement, and hydraulic jacks can be replaced in the event of malfunction. All devices are calibrated individually and certificates on each device will be submitted prior to commencing the bidirectional load test.

9.0 GUIDE TO POST-TEST GROUTING

Working pile is to be grouted after the test is completed. This section of method statement only serves as a guide on the grout mix and the grouting procedure. Grouting at site or the grouting system is to formally proposed and carried out at site by the contractor. The purpose of grouting is to fill up the voids created by the opening of the hydraulic jack(s) during testing. The voids are found in two (2) specific areas of the hydraulic jack assembly:

within the jack chamber(s) which are filled with water after the test; space immediately above the lower bearing plate of the hydraulic jack assembly that

is created due to the lifting of concrete from the debonded surface of the lower bearing plate during the opening of the hydraulic jack(s).

Preparing the grout. The grout used shall consist of cement grout with non shrink additive and water. NO sand should be used in the mix. The grout mixing and preparation shall be in accordance to the manufacturers instruction. Depending on the pump used to deliver the grout to the voids, the amount of water used can be adjusted to a suitable consistency (remaining within the specifications and guidelines from the cement manufacturer). It is recommended that the cement grout pass through a sieve so that lumps, if any, are effectively removed from the mix to prevent any untoward incident of hose clogging during grouting. Grouting the jack chamber(s). The original hydraulic hoses are used to deliver the grout mix. There are two (2) hoses for each hydraulic jack one serves as inlet and should be attached to the grout mixer and the other which serves as outlet should be open-ended to allow the discharge of water and subsequently excess grout during the entire process. At the commencement of grouting, water will flow out of the outlet, followed eventually by grout of the same viscosity and consistency to that which is pumped in through the inlet. This indicates that the grouting process is completed. The outlet should then be closed with suitable pressure applied before closing the inlet. Repeat the same procedure for other hydraulic jack(s).

Grouting the void above the lower bearing plate. Four (4) nos. of preinstalled grouting hoses are used for grouting. Grouting to the void between the steel plates as a result of jack opening is via the HDPE hose (or equivalent) as provided. There are normally two conditions for grouting the void:


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1. If jack opening is small after test, all the grouting hoses should be pump with water using suitable coupling connect to the pump with appropriate pressure applied one at a time to allow the seal of grouting hose that is near to the jack opening to break. Subsequently grouting can be carried out by pumping the grout into all the hoses with suitable pressure one at a time. The amount of grout used during this time should be monitor as compared to the theoretical volume required to ensure the void is been completely filled up.

2. If jack opening is reasonably big after test, grouting can be carried out without applying water pressure as the grouting hoses would have been tear off due to the jack opening. The amount of grout used during this time should be monitor as compared to the theoretical volume required to ensure the void is been completely filled up.

Quantity of grout to use. The quantity of grout required can be estimated (conservatively) based on the following formulas: (a) Grouting of hydraulic jacks:

Nominal maximum stroke of hydraulic jack

multiply by Area of jack based on nominal outer diameter

multiply by no. of hydraulic jacks used

multiply by 2 (provision for excess)

(b) Grouting of void above lower bearing plate:

Cross sectional area of pile based on nominal pile diameter multiply by

Nominal maximum stroke of hydraulic jack multiply by 2 (provision for excess)

Compression test During grouting, samples of grout can be taken and tested after a specific waiting time.


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Appendix A

Instrumentation Schematic Showing the Pile Layout for a Bidirectional Static Load Test


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Figure 1: Schematic Diagram of Bored Pile Layout


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Figure 2: Schematic Diagram of Annular Void Grouting


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Figure 3: Schematic Diagram of Jack Grouting

Bidirectional Static Load Test Method Statement Proposed Wisma Matex, Johor

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Figure 4: Layout of Hydraulic Jack Assembly


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Appendix B

Calculation of Hydraulic Jack Level


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Appendix C

Loading Schedule of Test Pile


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Loading Schedule of Test Pile:

Cycle Percentage of Working Load Minimum Holding

Time (mins)

1

0% 0 10% 10 20% 10 30% 10 40% 10 50% 10 60% 10 70% 10 80% 10 90% 10

100% 60 75% 10 50% 10 25% 10 0% 30

2

25% 10 50% 10 75% 10

100% 10 110% 10 120% 10 130% 10 140% 10 150% 10 160% 10 170% 10 180% 10 190% 10 200% 120 150% 10 100% 10 50% 10 0% 30

The loading stage of 100% and 200% shall be sustained at a constant magnitude until the rate of settlement for cell top and cell bottom is less than 0.25 mm/hr respectively and slowing down.


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Appendix D

Schematic Diagram of Testing Procedure


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hydraulic pump poweredusing air compressor

hydraulic pressuremonitored using

pressure transducer

pressure readinglog by datalogger

displacement readinglog by datalogger

displacement & pressurereading viewed on laptop

tell tale extensometer for pile top, cell top,

cell bottom and pile toe

hydraulic cell hoseconnect tomanifold

pressure dispersedinto hydraulic cellthrough manifold

Displacement vs. loadcurves plotted on the spot

FOR ILLUSTRATION ONLY


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Appendix E

Construction of Equivalent Top-Loaded Load Settlement Curve


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CONSTRUCTION OF THE EQUIVALENT TOP-LOADED LOAD-SETTLEMENT CURVE FROM THE RESULTS OF

BIDIRECTIONAL STATIC LOAD TEST (BDSLT)

Introduction: BDSLT can provide a good estimate of a curve showing the load versus settlement of a top-loaded driven or bored pile (drilled shaft) with the following assumptions, which is consider good sense and usually conservative:

1. The end bearing load-movement curve in a top-loaded shaft has the same loads for a given movement as the net (subtract buoyant weight of pile above hydraulic jack) end bearing load-movement curve developed by the bottom of the hydraulic jack when placed at or near the bottom of the shaft.

2. The side shear load-movement curve in a top-loaded shaft has the same net shear, multiplied

by an adjustment factor F for a given downward movement as occurred in the BDSLT for that same movement at the top of the jack in the upward direction. The same applies to the upward movement in a top-loaded tension test. Unless noted otherwise, a factor F=0.95 for compression in cohesionless soils and F=0.80 for tension tests in all soils is used.

3. The pile behaves as a rigid body, but include the elastic compressions that are part of the

movement data obtained from a bidirectional static load test (BDSLT). Procedure 1 interprets an equivalent top-load test (TLT) movement curve and procedure 2 corrects the effects of the additional elastic compressions in a TLT.

4. The part of the shaft below the hydraulic jack (one or multi level) has the same load-

movement behavior as when top-loading the entire shaft. The subsequent end bearing movement curve refers to the movement of the entire length of shaft below the jack.

Procedure 1: Figure A shows BDSLT results and Figure B shows the construction of equivalent top loaded settlement curve. Each of the curves shown has points numbered from 1 to 12 such that the same point number on each curve has the same movement magnitude. With the above assumptions, the equivalent curve can be constructed as follows: Select an arbitrary movement such as the 0.40 inches to give point 4 on the shaft side shear load movement curve in Figure A and record the load of 2,090 tons in shear at that movement. With the initial assumption of a rigid pile, the top of pile moves downward the same as the bottom. Therefore, find point 4 with 0.40 inches of upward movement on the end bearing load movement curve and record the corresponding load of 1,060 tons. Adding these two loads will give the total load of 3,150 tons due to side shear plus end bearing at the same movement and thus gives point 4 on the Figure B load settlement curve for an equivalent top-loaded test. Procedure 1 can be used to obtain all the points in Figure B up to the component that moved the least at the end of the test, in this case point 5 in side shear. Suitable hyperbolic curve fitting technique can be used for extrapolation of the side shear curve to produce end bearing movement data up to 12. Some judgment is required for deciding on the maximum number of data points to provide good fit with high correlation coefficient, r2. Using the same movement matching procedure described earlier, the equivalent curve to points 6 to 12 can be extended. The dashed line shown in Figure B, signify that this part of the equivalent curve depends partly on extrapolated data.


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If the data warrants, the extrapolations of both side shear and end bearing to extend the equivalent curve to a greater movement than the maximum measured (point 12) will be used. An appendix in this report gives the details of the extrapolation(s) used with the present BDSLT and shows the fit with the actual data. Procedure 2: The elastic compression in the equivalent top load test always exceeds that in the BDSLT. It produces more top movement and also additional side shear movement, which then generate more side shear, more compression, etc. An exact solution of this load transfer problem requires knowing the side shear vs. vertical movement (t-y) curves for a large number of pile length increments and solving the resulting set of simultaneous equations or using finite element or finite difference simulations to obtain an approximate solution for these equations. The attached analysis P.6 gives the equations for the elastic compressions that occur in the BDSLT with one or two levels of hydraulic jacks. Analysis P.7 gives the equations for the elastic compressions that occur in the equivalent TLT. Both sets of equations do not include the elastic compression below the hydraulic jack because the same compression takes place in both the BDSLT and the TLT. This is equivalent to taking l3 = 0. Subtracting the BDSLT from the TLT compression gives the desired additional elastic compression at the top of the TLT. The additional elastic compression is then added to the rigid equivalent curve obtained from Part 1 to obtain the final, corrected equivalent load-settlement curve for the TLT on the same pile as the actual BDSLT. Note that the above p.6 and p.7 give equations for each of three assumed patterns of developed side shear stress along the pile. The pattern shown in the center of the three is applicable to any approximate determined side shear distribution. Experience has shown the initial solution for the additional elastic compression, as described above, gives an adequate and slightly conservative (high) estimate of the additional compression versus more sophisticated load-transfer analyses as described in the first paragraph of this Part II. The analysis p.8 provides an example of calculated results in English units on a hypothetical 1-stage, single level BDSLT using the simplified method in Part II with the centroid of the side shear distribution 44.1% above the base of the hydraulic cell. Figure C compares the corrected with the rigid curve of Figure B. Page 9 contains an example equivalent to that above in SI units. The final analysis p.10 provides an example of calculated results in English units on a hypothetical 3-stage, multi level BDSLT using the simplified method in Part II with the centroid of the combined upper and middle side shear distribution 44.1% above the base of the bottom hydraulic jack. The individual centroids of the upper and middle side shear distribution lie 39.6% and 57.9% above and below the middle hydraulic jack, respectively. Figure E compares the corrected with the rigid curve. Page II contains an example equivalent to that above in SI units. Other Tests: The example illustrated in Figure A has the maximum component movement in end bearing. The procedures remain the same if the maximum test movement occurred in side shear. Then we would have extrapolated end bearing to produce the dashed-line part of the reconstructed top-load settlement curve. The example illustrated also assumes a pile top-loaded in compression. For a pile top-loaded in tension we would, based on Assumptions 2 and 3, use the upward side shear load curve in Figure A, multiplied by the F = 0.80 noted in Assumption 2, for the equivalent top-loaded displacement curve.


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Expected Accuracy: There are only five series of tests that provide the data needed to make a direct comparison between actual, full scale, top-loaded pile movement behaviour and the equivalent behaviour obtained from a BDSLT by the method described herein. These involved three sites in Japan and one in Singapore, in a variety of soils, with three compression tests on bored piles (drilled shafts), one compression test on a driven pile and one tension test on a bored pile. The largest bored pile had a 1.2 m diameter and a 37 m length. The driven pile had a 1-m increment modular construction and a 9 m length. The largest top loading = 28 MN (3,150 tons). The following references detail the aforementioned Japanese tests and the results therefore:

Kishida H. et al., 1992, Pile Loading Tests at Osaka Amenity Park Project, Paper by Mitsubishi Co., also briefly described in Schmertmann (1993, see bibliography). Compares one drilled shaft in tension and another in compression.

Ogura, H. et al., 1995, Application of Pile Toe Load Test to Cast-in-place Concrete Pile and Precast Pile, special volume Tsuchi-to-Kiso on Pile Loading Test, Japanese Geotechnical Society, Vol. 3, No. 5, Ser. No. 448. Original in Japanese. Translated by M.B. Karkee, GEOTOP Corporation. Compares one drilled shaft and one driven pile, both in compression.

We compared the predicted equivalent and measured top load at three top movements in each of the above four Japanese comparisons. The top movements ranged from inch (6 mm) to 40 mm, depending on the data available. The (equiv./meas.) ratios of the top load averaged 1.03 in the 15 comparisons with a coefficient of variation of less than 10%. These available comparisons help support the practical validity of the equivalent top load method described herein. L.S. Peng, A.M. Koon, R. Page and C. W. Lee report the results of a class-A prediction by others of the TLT curve from a BDSLT on a 1.2 m diameter, 37.2 m long bored pile in Singapore, compared to an adjacent pile with the same dimensions actually top-loaded by kentledge. They report about a 4% difference in ultimate capacity and less than 8% difference in settlements over the 1.0 to 1.5 times working load range comparable to the accuracy noted above. Their paper has the title OSTERBERG CELL TESTING OF PILES, and was published in March 1999 in the Proceedings of the International Conference on Rail Transit, held in Singapore and published by the Association of Consulting Engineers Singapore. B.H. Fellenius has made several finite element method (FEM) studies of a BDSLT in which he adjusted the parameters to produce good load-deflection matches with the BDSLT up and down load-deflection curve. He then used the same parameters to predict the TLT deflection curve. We compared the FEM-predicted curve with the equivalent load-deflection predicted by the previously described Part I and II procedures, with the results again comparable to the accuracy noted above. A paper by Fellenius et. al. titled BDSLT and FE Analysis of a 28 m Deep Barrette in Manila, Philippines, awaiting publication in the ASCE Journal of Geotechnical and Environmental Engineering, details one of the comparisons. Limitations: The engineer using these results should judge the conservatism of the aforementioned assumptions and extrapolation(s) before utilizing the results for design purposes. For example, brittle failure behaviour may produce movement curves with abrupt changes in curvature (not hyperbolic). However, the hyperbolic fit method and the assumptions used usually produce reasonable equivalent top load settlement curves.

Feb, 2007


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Example of the Construction of an Equivalent Top-Loaded Settlement Curve (Figure B) From BDSLT Results (Figure A)

Maximum Net Load from BDSLT


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Theoretical Elastic Compression in BDSLT Based on Pattern of Development Side Shear Stress

BDSLT = 1 + 2

BDSLT = 1 + 2


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Theoretical Elastic Compression in Top Loaded Test Based on Pattern of Development Side Shear Stress

Component loads Q selected at the same () BDSLT.


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Example Calculation for the Additional Elastic Compression Correction for Single Level Test (English Units)

Given: C1 = 0.441

AE = 3820000 kips (assumed constant throughout test) 0 = 5.9 ft 1 = 48.2 ft (embedded length of shaft above hydraulic jack)

2 = 0.0 ft 3 = 0.0 ft Shear reduction factor = 1.00 (cohesive soil)

BDSLT (mm) QA (MN)

QA (MN) P

(MN) TLT (mm)

BDSLT (mm) (mm)

BDSLT + (mm)

0.000 0 0 0 0.000 0.000 0.000 0.000 0.100 352 706 1058 0.133 0.047 0.086 0.186 0.200 635 1445 2080 0.257 0.096 0.160 0.360 0.300 867 1858 2725 0.339 0.124 0.215 0.515 0.400 1061 2088 3149 0.396 0.139 0.256 0.656 0.600 1367 2382 3749 0.478 0.159 0.319 0.919 0.800 1597 2563 4160 0.536 0.171 0.365 1.165 1.000 1777 2685 4462 0.579 0.179 0.400 1.400 1.200 1921 2773 4694 0.613 0.185 0.427 1.627 1.500 2091 2867 4958 0.651 0.191 0.460 1.960 1.800 2221 2933 5155 0.680 0.196 0.484 2.284 2.100 2325 2983 5308 0.703 0.199 0.504 2.604 2.500 2434 3032 5466 0.726 0.202 0.524 3.024


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Example Calculation for the Additional Elastic Compression Correction for Single Level Test (SI Units)

Given: C1 = 0.441 AE = 17000 MN (assumed constant throughout test)

0 = 1.80 m 1 = 14.69 m (embedded length of shaft above hydraulic jack) 2 = 0.00 m 3 = 0.00 m Shear reduction factor = 1.00 (cohesive soil)

BDSLT (mm) QA (MN)

QA (MN) P

(MN) TLT (mm)

BDSLT (mm) (mm)

BDSLT + (mm)

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2.54 1.57 3.14 4.71 3.37 1.20 2.17 4.71 5.08 2.82 6.43 9.25 6.52 2.45 4.07 9.15 7.62 3.86 8.27 12.12 8.61 3.15 5.46 13.08

10.16 4.72 9.29 14.01 10.05 3.54 6.51 16.67 15.24 6.08 10.60 16.68 12.14 4.04 8.10 23.34 20.32 7.11 11.40 18.50 13.60 4.34 9.26 29.58 25.40 7.90 11.94 19.85 14.70 4.55 10.15 35.55 30.48 8.55 12.33 20.88 15.55 4.70 10.85 41.33 38.10 9.30 12.75 22.05 16.53 4.86 11.67 49.77 45.72 9.88 13.05 22.93 17.27 4.97 12.29 58.01 53.34 10.34 13.27 23.61 17.84 5.06 12.79 66.13 63.50 10.83 13.48 24.31 18.44 5.14 13.30 76.80


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Example Calculation for the Additional Elastic Compression Correction for Multi Level Test (English Units)

Given: C1 = 0.441 C2 = 0.579 C3 = 0.396

AE = 3820000 kips (assumed constant throughout test) 0 = 5.9 ft

1 = 30.0 ft (embedded length of shaft above mid-jack) 2 = 18.2 ft (embedded length of shaft between hydraulic jack) 3 = 0.0 ft Shear reduction factor = 1.00 (cohesive soil)

BDSLT (mm) QA (MN)

QB (MN)

QB (MN)

P (MN)

TLT (mm) BDSLT (mm)

(mm) BDSLT +

(mm) 0.000 0 0 0 0 0.000 0.000 0.000 0.000 0.100 352 247 459 1058 0.133 0.025 0.107 0.207 0.200 635 506 939 2080 0.257 0.052 0.205 0.405 0.300 867 650 1208 2725 0.339 0.067 0.272 0.572 0.400 1061 731 1357 3149 0.396 0.075 0.321 0.721 0.600 1367 834 1548 3749 0.478 0.085 0.393 0.993 0.800 1597 897 1666 4160 0.536 0.092 0.444 1.244 1.000 1777 940 1745 4462 0.579 0.096 0.483 1.483 1.200 1921 971 1802 4694 0.613 0.099 0.513 1.713 1.500 2091 1003 1864 4958 0.651 0.103 0.548 2.048 1.800 2221 1027 1907 5155 0.680 0.105 0.575 2.375 2.100 2325 1044 1939 5308 0.703 0.107 0.596 2.696 2.500 2434 1061 1971 5466 0.726 0.109 0.618 3.118


Page 31

Example Calculation for the Additional Elastic Compression Correction for Multi Level Test (SI Units)

Given: C1 = 0.441 C2 = 0.579 C3 = 0.396 AE = 17000 MN (assumed constant throughout test) 0 = 1.80 m 1 = 9.14 m (embedded length of shaft above mid-jack)

2 = 5.55 m (embedded length of shaft between hydraulic jack) 3 = 0.00 m Shear reduction factor = 1.00 (cohesive soil)

BDSLT (mm) QA (MN)

QB (MN)

QB (MN)

P (MN)

TLT (mm) BDSLT (mm)

(mm) BDSLT +

(mm) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2.54 1.57 1.10 2.04 4.71 3.37 0.64 2.73 5.27 5.08 2.82 2.25 4.18 9.25 6.52 1.31 5.21 10.29 7.62 3.86 2.89 5.37 12.12 8.61 1.69 6.92 14.54

10.16 4.72 3.25 6.04 14.01 10.05 1.90 8.15 18.31 15.24 6.08 3.71 6.89 16.68 12.14 2.17 9.97 25.21 20.32 7.11 3.99 7.41 18.50 13.60 2.33 11.27 31.59 25.40 7.90 4.18 7.76 19.85 14.70 2.44 12.26 37.66 30.48 8.55 4.32 8.02 20.88 15.55 2.52 13.03 43.51 38.10 9.30 4.46 8.29 22.05 16.53 2.61 13.92 52.02 45.72 9.88 4.57 8.48 22.93 17.27 2.67 14.60 60.32 53.34 10.34 4.64 8.62 23.61 17.84 2.71 15.13 68.47 63.50 10.83 4.72 8.76 24.31 18.44 2.76 15.68 79.18


Page 32

Appendix F

Samples Plots from a Typical Test


Page 33

-20.0-18.0-16.0-14.0-12.0-10.0-8.0-6.0-4.0-2.00.02.04.06.08.0

10.012.014.016.018.020.022.024.026.028.030.0

0 250 500 750 1000 1250 1500 1750 2000 2250 2500 2750 3000 3250 3500

Disp

lacem

ent (m

m)

Unidirectional Load (tonnes)

Proposed Condominium Development of 33 Storey on Lot 1311W TS 24 Angullia Park / Cuscaden Walk, SingaporeBidirectional Static Load Test on Pile No. UTPtested on 21st October 2009CHART 1 - Load-Movement Plot

Pile Top Cell Top Cell Bottom Pile Bottom

40.0

35.0

30.0

25.0

20.0

15.0

10.0

5.0

0.00 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500

Settle

ment

(mm)

Load (tonnes)

Proposed Condominium Development of 33 Storey on Lot 1311W TS 24 Angullia Park / Cuscaden Walk, SingaporeBidirectional Static Load Test on Pile No. UTPtested on 21st October 2009CHART 2 - Equivalent Top Load vs Settlement Curve

Settlement (Rigid Pile) Settlement (Adjusted for Elastic Compression)


Page 34

Appendix G

BDSLT Risk Assessment


Page 35

Operation Hazard or Potentially Hazardous Hazard

Effec

t

Prob

ability

Risk

Control to Mimimise Risk

Resid

ual R

isk

Use of Personal Protective Equipment

General site hazard M M M

Wear hard hat, safety boot. If required use ear protection, mask, reflective jacket, safety glasses and glove

LProximity of Site Operation

Injury to person M M M

Keep clear of piling or excavation activity. Ensure work area is away and located in safe area.

LProximity to welding operation

Eye damage, burn injury H M M

Ensure welding activity is carried out by trained personnel only. Use screen where possible. Keep safe distance from welding activity

L

Lifting and crane operation

Injury to person H L H

keep safe distance from any lifting / cranage operation. Used trained slingers and banksmen

LUse of Tools Injury to

person using tools

M L M Check all hand tools are in good condition. Wear glove where necessary.

LUse of chemical Eye / skin

hazard M M MUse safety glasses / goggles and gloves when using any hazardous materials / chemicals. Standby water for cleaning purpose.

L

Ground and working area conditions

Slip and trip hazard M M M

Provide adequate walkway and working area. Keep working area clear of obstruction / debris.

LUnforeseen site danger Nature

unknown H L MDiscuss safety with Safety Officer beforehand. Identify gathering area in case of emergency.

L

FINAL ASSESSMENT OVERALL RISK L

RISK ASSESSMENT FORMGeneral Operation


Page 36


Effec

t

Prob

ability

Risk

Control to Mimimise Risk

Resid

ual R

isk

Attached instrumentation to cages

Injury to person L L L

Use trained personnel. Work from outside the cage. Entry to cage should only be made in exceptional circumstances and only if egress is safe.

L

Attach of hydraulic cell assembly to cage

Injury to person due to lifting / welding activity

L H HUse trained personnel. Use established safe practice for welding and lifting. Keep clear distance from any lifting and welding activity.

L

Make hose connection inside cage

Slip and trip hazard L H M

Use trained personnel. Always to have a assistant around to ensure safety work. L

Fixing pipes inside upper cages as cages are spliced

Injury to person L H M Use trained personnel. Wear glove and

safety glasses if needed.L

Tying of hoses to the cages as lowered into hole

Injury to person L H M

Ensure proper instruction is given to crane operator. Ensure work area clear of mud / debris.

L



Effec

t

Prob

ability

Risk Control to Mimimise Risk

Resid

ual

Risk

Pressurised Hydraulic hoses leakage / burst

Injury to person M L M

Ensure adequate strength of hose / correct rating. Check all hoses prior to work start. Only allow authorised personnel into working area.

L

Pressurised air hose leakage / burst

Injury to person M L M Ensure adequate strength of hose / correct rating. Check all hoses prior to work start.

Check correct operation and quality of air.L

Electric shock Injury to person H L M

Ensure proper outdoor electrical connection are used. Check all cables before connection. Use only 110V supplies where avaliable.

L


RISK ASSESSMENT FORMBDSLT Installation

RISK ASSESSMENT FORMBDSLT Testing


Page 37

Appendix H

Contractor Worksheet


Page 38

Strainstall Malaysia Contractor's Worksheet Project Name: Date: Project Location: Country: Number of Test on Site: 1 FIELD RESPONSIBILITIES FOR EACH INSTALLATION Equipment / Supplies Contractor SSM Remarks

Reinforcement Cage Steel Bearing Plates Hydraulic Jack, Instrumentation 1/2" Iron Pipe (6 m length) 6 times pile length 3/4" Iron Pipe (6 m length) 1 length Lifting Equipment Two cranes preferred Right-angle rebar 200 x 200 mm; 25 mm HDPE hose If applicable Welding Personnel Welding Equipment & Torches Grinder Hand Tools Working Area Personal Safety Equipment

Procedure Fabrication of Reinforcement Cage Hydraulic Jack Assembly Attach Hydraulic Jack to Cage SSM Observe Construct funnel SSM Observe Attach Instruments to Cage Excavation of Bored Pile Per Specification Inspection of Bored Pile Per Specification Quality Control of Pile Per Specification Lifting of Cage SSM Observe Lowering of Cage with Jack Attached SSM Observe Attachment of Hoses to Upper Cages SSM Observe Lapping of Reinforcement Cages SSM Observe Per Specification Concrete Placement in Pile SSM Observe Per Specification


Page 39

Strainstall Malaysia Contractor's Worksheet Project Name: Date: Project Location: Country: Number of Test on Site: 1 FIELD RESPONSIBILITIES FOR EACH TESTINGEquipment / Supplies Contractor SSM Remarks

Welding Personnel Welding Equipment & Torches Grinder Hand Tools Air Compressor 175cfm Fresh Water 100 L Reference Beam & Supports Weather Protection (sun / rain) Test Instrumentation Test Equipment Surveyor's Level & Tripod Grout Mixer and Pump Lighting If necessary

Procedure Concrete Strength Test Setup of Reference Beam SSM Observe Lowering of Telltale Rod into Iron Pipe SSM Observe Setup of Weather Protection To cover pile and testing area Setup of Test Instrumentation Operation of Test Equipment Recording of Test Data Submission of Final Test Report

bdslt method statement _bt maung.pdf

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