Jack-in Piling Environmental Friendly Piling System



Similar documents
Geotechnical Investigation Reports and Foundation Recommendations - Scope for Improvement - Examples

Figure A-1. Figure A-2. continued on next page... HPM-1. Grout Reservoir. Neat Cement Grout (Very Flowable) Extension Displacement Plate

PILE FOUNDATIONS FM 5-134

Step 11 Static Load Testing

Dead load (kentledge) A structure over the test pile. Ground anchorage either by tension piles or ground anchors. Bi-directional (Osterberg-cell)

Dynamic Load Testing of Helical Piles

Geotechnical Measurements and Explorations Prof. Nihar Ranjan Patra Department of Civil Engineering Indian Institute of Technology, Kanpur

Design of pile foundations following Eurocode 7-Section 7

Design and Construction of Auger Cast Piles

METHOD OF STATEMENT FOR STATIC LOADING TEST

Anirudhan I.V. Geotechnical Solutions, Chennai

USE OF CONE PENETRATION TEST IN PILE DESIGN

DESIGN OF PILES AND PILE GROUPS CONSIDERING CAPACITY, SETTLEMENT, AND NEGATIVE SKIN FRICTION

SUGGESTION ABOUT DETERMINATION OF THE BEARING CAPACITY OF PILES ON THE BASIS OF CPT SOUNDING TESTS

Laterally Loaded Piles

ALLOWABLE LOADS ON A SINGLE PILE

Instrumentations, Pile Group Load Testing, and Data Analysis Part II: Design & Analysis of Lateral Load Test. Murad Abu-Farsakh, Ph.D., P.E.

A case study of large screw pile groups behaviour

CHAPTER 9 LONG TERM MONITORING AT THE ROUTE 351 BRIDGE

SPECIFICATION FOR DYNAMIC CONSOLIDATION / DYNAMIC REPLACEMENT

FOUNDATION DESIGN. Instructional Materials Complementing FEMA 451, Design Examples

Design, Testing and Automated Monitoring of ACIP Piles in Residual Soils

Method Statement FOR. Soil Investigation

Method Statement for Static Load Testing (Compression) for Micropiles

Lymon C. Reese & Associates LCR&A Consulting Services Tests of Piles Under Axial Load

The advantages and disadvantages of dynamic load testing and statnamic load testing

APPENDIX A PRESSUREMETER TEST INTERPRETATION

CEEN Geotechnical Engineering Laboratory Session 7 - Direct Shear and Unconfined Compression Tests

Field tests using an instrumented model pipe pile in sand

vulcanhammer.net This document downloaded from

How To Design A Foundation

Comprehensive Design Example 2: Foundations for Bulk Storage Facility

Table of Contents 16.1 GENERAL Overview Responsibilities

Design of pile foundations following Eurocode 7

Eurocode 7 - Geotechnical design - Part 2 Ground investigation and testing

EVALUATION OF BEARING CAPACITY OF PILES FROM CONE PENETRATION TEST DATA

INSITU TESTS! Shear Vanes! Shear Vanes! Shear Vane Test! Sensitive Soils! Insitu testing is used for two reasons:!

PDCA Driven-Pile Terms and Definitions

2009 Japan-Russia Energy and Environment Dialogue in Niigata S2-6 TANAKA ERINA

Page B-1 Hubbell Power Systems, Inc. All Rights Reserved Copyright 2014 LOAD TESTS

Improvement in physical properties for ground treated with rapid impact compaction

ENCE 4610 Foundation Analysis and Design

Pile test at the Shard London Bridge

FINITE ELEMENT STUDY ON STATIC PILE LOAD TESTING

Geotechnical Investigation Test Report

SAMPLE GUIDE SPECIFICATIONS FOR OSTERBERG CELL LOAD TESTING OF DEEP FOUNDATIONS

STATIC CONE PENETRATION TEST CPT1

CHAPTER 1 INTRODUCTION

TYPES OF PIERS USED IN NORTH AND EAST TEXAS RESIDENTIAL FOUNDATION REPAIR

RECENT EXPERIENCES WITH BI-DIRECTIONAL STATIC LOAD TESTING

CE-632 Foundation Analysis and Design

METHOD STATEMENT HIGH STRIAN DYNAMIC TESTING OF PILE. Prepared by

An Automatic Kunzelstab Penetration Test

Comparison Between Dynamic and Static Pile Load Testing

vulcanhammer.net Visit our companion site

Site Investigation. Some unsung heroes of Civil Engineering. buried right under your feet. 4. Need good knowledge of the soil conditions

Local Authority Building Control Technical Information Note 3 Driven and In-situ Piled Foundations

GEOTECHNICAL ENGINEERING FORMULAS. A handy reference for use in geotechnical analysis and design

GUIDELINE FOR HAND HELD SHEAR VANE TEST

Use and Application of Piezocone Penetration Testing in Presumpscot Formation

Practice of rapid load testing in Japan

KWANG SING ENGINEERING PTE LTD

Standard Test Method for Mechanical Cone Penetration Tests of Soil 1

DYNAMIC TESTING OF MICROPILES. COMPARISON OF STATIC AND DYNAMIC TEST RESULTS

Proceedings of the ASME 28 TH International Conference on Ocean, Offshore and Arctic Engineering OMAE2009 May 31 June 5, 2009, Honolulu, Hawaii, USA

INDIRECT METHODS SOUNDING OR PENETRATION TESTS. Dr. K. M. Kouzer, Associate Professor in Civil Engineering, GEC Kozhikode

Toe Bearing Capacity of Piles from Cone Penetration Test (CPT) Data

Drained and Undrained Conditions. Undrained and Drained Shear Strength

Standard penetration test (SPT)

Cone Penetration Testing in Geotechnical Practice. Tom Lunne Peter K. Robertson John J.M. Powell

DESIGNING STRUCTURES IN EXPANSIVE CLAY

Micropiles Reduce Costs and Schedule for Merchant RR Bridge Rehabilitation

CE 366 SETTLEMENT (Problems & Solutions)

PROVA DINAMICA SU PALI IN ALTERNATIVA ALLA PROVA STATICA. Pile Dynamic Load test as alternative to Static Load test

INTRODUCTION TO SOIL MODULI. Jean-Louis BRIAUD 1

Design and installation of steel open end piles in weathered basalt. Luc Maertens*

Determination of Thermal Conductivity of Coarse and Fine Sand Soils

The design of foundations for high-rise buildings

Federation of Piling Specialists Testing Datasheet No 1

Ground improvement using the vibro-stone column technique

Validation of methods for assessing tunnelling-induced settlements on piles

SUPPLEMENTAL TECHNICAL SPECIFICATIONS BI-DIRECTIONAL STATIC LOAD TESTING OF DRILLED SHAFTS

Method Statement. Static Pile Load Test

Driven Concrete Pile Foundation Monitoring With Embedded Data Collector System

Module 1 : Site Exploration and Geotechnical Investigation. Lecture 4 : In-situ tests [ Section 4.1: Penetrometer Tests ] Objectives

How To Model A Shallow Foundation

English version Version Française Deutsche Fassung. Eurocode 7 - Geotechnical design - Part 2: Ground investigation and testing

ATLAS RESISTANCE Pier Foundation Systems

ASSESSMENT OF SHEAR WAVE VELOCITY FROM INDIRECT INSITU TESTS

RECENT ADVANCES IN THE DESIGN OF PILES FOR AXIAL LOADS, DRAGLOADS, DOWNDRAG, AND SETTLEMENT

New construction Repairing failed or old foundations Retrofit foundations Permanent battered piers Machinery/equipment foundations

NEGATIVE SKIN FRICTION AND SETTLEMENT OF PILES. Dr. Bengt H. Fellenius, P. Eng. University of Ottawa, Canada

HAULBOWLINE, CORK STATIC CONE PENETRATION TESTS FACTUAL REPORT

FRANKIPILE. High Pile Loads Optimum Adaptation to Foundation Soil Low-noise Manufacturing Process

Geotechnical Testing Methods II

c. Borehole Shear Test (BST): BST is performed according to the instructions published by Handy Geotechnical Instruments, Inc.

Transcription:

Jack-in Piling Environmental Friendly Piling System Part 1 - Chris Loh 7 Nov 12 CSC HOLDINGS LIMITED

Gracious Piling Environmental Friendly Low Noise No Vibration Jack-in Piling

How Many Decibels? Permissible Leq 75dB (12 hours) within 15m

How Far Have We Gone Since 24? length of piles installed Singapore To Jakarta

Contents Method of Jack-in Piling System Installation Process Machine Movement and Installation Process (Video) Advantages of Jack-in Piling Mitigating Measures Jack-in Piling Machines Completed High Rise Buildings Projects Some Valued Clients To Conclude

Method of Jack-in Piling System CSC HOLDINGS LIMITED

Method of Jack-in Piling System A modern technique by which pre-formed piles (e.g. Prestressed Spun Piles, Precast RC Piles, H-Piles, Steel Pipe Piles) are hydraulically jacked into the ground as displacement piles

Installation Process CSC HOLDINGS LIMITED

Installation Process Pile is jacked into the ground with a jack-in force adjusted in steps up to between 1.8 times - 2.5 times working load Jacking will continue until practical refusal where jack-in force is released and reapplied twice Downward movement of the pile between the two cycles is then measured and checked against the set criteria

Machine Movement and Installation Process (Video) CSC HOLDINGS LIMITED

Machine Movement (Video)

Installation Process (Video)

Advantages of Jack-in Piling CSC HOLDINGS LIMITED

Advantages of Jack-in Piling Environmental Friendly - Low Noise - Vibration Free - Minimal Spoils Disposal Able to achieve Good Verticality Lower Risk of machine toppling as compared with conventional leader type machines Every pile is jacked up to between 1.8 times - 2.5 times working load

Mitigating Measures CSC HOLDINGS LIMITED

Mitigating Measures Relief Boring Pre-Boring at Piling Point

Jack-in Piling Machines CSC HOLDINGS LIMITED

Jack-in Piling Machines Low Capacity Machines - 1 to 13 tons

Jack-in Piling Machines Medium Capacity Machines - 24 to 42 tons

Jack-in Piling Machines High Capacity Machines - 6 to 8 tons

Completed High Rise Building Projects CSC HOLDINGS LIMITED

Completed High Rise Building Projects Livia Condominium 17 Storey 151 RC Piles & Spun Piles RC Piles 25mm, 3mm, 35mm and 4mm Spun Piles 5mm and 6mm Piles Capacity 6tons, 85tons, 1tons, 16tons, 125tons and 17tons

Completed High Rise Building Projects Twin Waterfalls 17 Storey 15 Spun Piles Spun Piles 4mm, 5mm and 6mm Piles Capacity 1tons, 15tons and 215tons

Completed High Rise Building Projects Austville Residences 18 Storey 115 Spun Piles RC Piles 25mm Spun Piles 5mm and 6mm Piles Capacity 13tons, 187tons and 25tons

Completed High Rise Building Projects DBSS @ AMK Street 52 3 Storey 1293 Spun Piles Spun Piles 4mm, 5mm and 6mm Piles Capacity 118tons, 169tons and 231tons

Some Valued Clients CSC HOLDINGS LIMITED

Some Valued Clients

To Conclude Environmental Friendly Suitable for all types of Pre-formed piles Proven to be viable foundation system for high rise buildings Piles are load tested during installation

Thank You CSC HOLDINGS LIMITED

Jack-in Piling Environmental Friendly Piling System Part 2 Gwee Boon Hong 7 Nov 212 CSC HOLDINGS LIMITED

Contents. DESIGN CONSIDERATIONS DESIGN PARAMETERS EVALUATION BASED ON INSTRUMENTATION RESULTS (Case Study : Old Alluvium Formation) JACK-IN PILE PERFORMANCE USING DIFFERENT JACK-IN FORCE DURING INSTALLATION (Case Study : Tuas South Avenue - Jurong Formation)

JACK-IN PILING DESIGN CONSIDERATIONS

Jack-in Pile Design Structural Considerations Qa =.25 (fcu fpe) * Ac Qa : Allowable structural axial capacity fcu : Compressive strength of concrete at 28 days fpe : Effective prestress in concrete Ac : Cross-sectional area of concrete Geotechnical Considerations Ultimate geotechnical capacity is determined by : Static formula on the basis of soil test Termination criteria using resistance measured during pile installation Verify performance of piles designed by above methods using static load test For quality control purpose, PDA and PIT are also carried out

Design Parameters In Accordance with CP4:23 Ultimate geotechnical axial capacity Qu = fs x As + qb x Ab Shaft Resistance : fs = Ks.N; Ks = 2 to 5 ; (limiting to 2kPa) Base Resistance: qb= Kb.4.N; Kb = 6 to 9 ; (limiting to 18,kPa for soil) For rock, qb = lesser of strength of pile material and unconfined compressive strength of rock Factor of Safety : Shaft Resistance = 2.5 Base Resistance = 2.5 Ks and Kb are related to the characteristics of soil & method of installation Higher value of Ks and Kb may be adopted if substantiated by sufficient instrumented load test in similar soil condition

Set / Termination Criteria Wide variations in termination ( set ) criteria for jacked piles Min jacked force = K x design working load (K varies between 1.8 to 2.5) Holding time = 3~6 seconds Max allowable settlement of 2mm for 2 or more consecutive cycles In Singapore context, termination criteria using min jacked force of 2 x WL and set criteria of 2mm between two jack cycles is commonly adopted Final acceptance criteria for the installed piles need to be verified by static pile load test

CASE STUDY 1 DESIGN PARAMETERS EVALUTION BASED ON INSTRUMENTATION RESULTS

Case Study 1 - Punggol View Pri Sch (Old Alluvium) 2 4 Unit Shaft Resistance (kpa) Actual 6 8 1-1 12 13 1 15 2 25 5 1 15-5 -5-5 -1-1 -15-15 -2-2 -2-25 -25-25 -3-3 -3-35 -35-35 -4-4 -4-45 -45-45 -5-5 Back Analysis -1 1-15 5 Ultimate Pile Capacity (kn) CS 2-5 Unit End Bearing (kpa) MS 12-15 2 4 6 8 JIF=2.1xWL 443 (2.1xWL) SPT-N Design Pile did not fail at 3xWL 17-2 35 Depth (m) SM 35-25 13-3 23 15-35 -4 Design SM SF>2.5 CS 17 28 MS 1m difference in pile length = $$ 36 59 1-45 68-5 -55 SM 1 1-5 q (Spun Pile diam. 6mm) -55-55 q 1-65 -7 fs -6 q qb q F.O.S -65-7 -55 Qb - Design Geotechnical Capacity q -6 Qs - Design Structural Capacity = 21 kn = Ks.N, Ks = 2. to-62.5 (limited to 12 kpa) = 4.N.Kb Kb = 5 (limited to 75 kpa ) -65 = 2.5-7 Qult - Design -6 JIF -65-7 Qult - Back Analysis (Based on Ins Result)

Load Distribution 1 2 3 4 5 6 7 634 CS 2 5625 12 15 12 8.4 19 1 MS 12 15 81 SM 1177 SM 35 25 13 23 3 23 18 56 4 594 1743 35 36 59 5 36 45 SM 4 4 SPT 1 MS 28 MS 68 2.5 Force Reading 28 45 2.4 3.1 35 43 17 4.5 CS 46 15 25 3 858 CS SM 4.7 Depth (m) Depth (m) SM 295 15 5.4 2 121 35 35 D ep th (m ) 5 12 2 13 1 17 3468 35 5 CS 9 1 4385 MS 2 35 2 1 17 3 15 13 13 1 25 1 2 5 5 15 5 1 Ks (fs/nav) fs (kpa) Loads (kn) Soil Layer Layer 59 1 SM 5 Low unit end bearing (152 kpa), Not fully mobilized fs 45 SPT Soil Layer Layer 5 CP4 Ks = 2N Average Ks = 4.4N CP4 Ks = 5N

Load Settlement Curve 8 Cycle-1 Cycle-2 Cycle-3 7 24.12; 634 Load at Top (kn) 6 5 13.54; 4326 4 3 6.35; 29 2 1 5 1 15 2 Settlement at Pile Head (mm) 25 3

Displacement Vs Mobilized Resistance 2 2-6m End Bearing 6-12m 12-18m 18-24m 15 28.5-31.5m 31.5-34.5m 34.5-36.5m 1 5 Unit End Bearing (kpa) Unit Shaft Resistance (kpa) 24-28.5m 15 1 5 5 1 15 Displacement (mm) 2 25 5 1 15 2 25 Displacement (mm) Max unit shaft friction is mobilized at average pile displacement between soil stratum of 12mm or 2% of pile diameter. Mobilized unit end bearing was 152 kpa at pile toe displacement of 5.89mm or.9% of pile diameter.

Design Parameters Evaluation, Ks & Kb Assumed Ks 2 to 2.5 Kb 5 Measured 4.4 12 kpa CP-4 2 to 5 2 kpa 2.2 152 kpa ** 6 to 9 18 kpa ** Not fully mobilized

Mobilized Shaft Resistance (Old Alluvium) 45 Non-displacement Pile (NDP) 4 Displacement Pile (DP) 35 Unit Shaft Resistance (kpa) CP-4 Ks= 5N 3 CP-4 Ks=3N 25 2 CP-4 Ks=2N 15 CP-4 Ks=1.5N 1 5 5 1 15 2 25 3 35 4 45 5 55 6 65 7 75 8 85 9 N-SPT Compilation of ULT (Instrumented) results from different piling systems within Punggol sites

CASE STUDY 2 EFFECT OF JACK-IN FORCE ON JACK-IN PILE PERFORMANCE AT TUAS SOUTH AVENUE - In collaboration with NUS (29) -

Pile & Instrumentation Layout Plan 3 3 15m (25D) TP2 CPT1 CPT1b CPT3a CPT2a CPT1a CPT3 CPT2 CPT1 CPT1b CPT1a CPT2 CPT2a CPT3 TP3 P1' 3 3 CPT3a 3 CPT4a CPT3a CPT4 CPT1, CPT1a, CPT1b, m 3 8.4 CPT2a (14 D) CPT1a CPT1b CPT3 CPT2 CPT1 TP1 8.4 m D 4 1 ( ) : 2r (.6m) from center of spun pile CPT2, CPT2a, : 3r (.9m) from center of spun pile Before pile installation CPT3, CPT3a, : 5r (1.5m) from center of spun pile After pile installation CPT4, CPT4a After load test ; 1r (3.m) from center of spun pile

Soil Stratigraphy TP2 (JIF = 2xWL=586kN) 12m 4m TP1 (JIF=1.5xWL=4395kN) FILL (Loose to Medium Dense SAND) SPT-N of 5 to 12 KALLANG FORMATION (Very Soft to Soft Marine CLAY) SPT-N of 2 to 4 Residual Soil S VI (Stiff to Very Stiff Sandy CLAY) JURONG FORMATION 4m SPT-N of 1 to 2 1m Completely Weathered Siltstone/Sandstone S V (Stiff to Very Stiff Sandy CLAY) JURONG FORMATION SPT-N of 2 to 4 29.9m TP3 (JIF=2.25xWL=6592.5kN) 28.7m 31.7m JURONG FORMATION, Completely Weathered Siltstone/Sandstone S V (Hard Sandy CLAY, N>6)

Installation Record TP1 (1.5xWL=4395kN) Jack-In Force (kn) 1 2 3 4 5 6 7 2 4 6 8 1 2 Depth (m) 8-15 23 19 71 35 TP-2 CS (S-V) TP-3 CS (S-V) 19 set at 28.7m 1-3 29 1 CS (S-V) 1-35 -35-35 MS (S-V) 17 18 28-3 1 TP-1 16 41 62 MS (S-V) 14-25 35-3 4 MS (S-V) 27-25 MS (S-V) 36-2 21 MS (S-V) 25 3 CS (S-VI) 38 15-25 2 1 27 34 25 CS (S-VI) 28-2 marine CLAY 1 18 2 8 5-15 11-2 -1 m arine CLAY 4 MS (S-VI) 1 4 2 9 1 8 9 8-1 m arine CLAY 6 SM (Fill) 14-5 8 4 4 13 SM (Fill) 11 9 2 2 9 11-5 4-1 1 11 SM (Fill) 8-15 8 4 9-5 15 6 13 1 4 1 5 TP3 (2.25xWL=6592.5kN) TP2 (2xWL=586kN) set at 29.9m set at 31.7m

Test program and Test Arrangement Kentledge reaction system (TP1 and TP3) Jack-in rig counter-weight reaction system (TP2)

Load Test Results Load LoadSettlement SettlementCurve Curve(Combine (CombinePlot) Plot) 2.5xWL (7325 kn) 1 1 TP1=29.9mm TP2=26.mm 9 9 TP3=26.5mm 98.24mm 98.24mm 8 8 (at 2.99xWL (At 2.99xWL = 8762kN) = 8762kN) 85.9mm Load at at Top Top (kn) (kn) Load 7 7 85.9mm (at 2.62xWL (At 2.62xWL = 769kN) = 769kN) 6 6 2xWL (586 kn) 5 5 TP1=18.8mm TP1' TP1' TP2=18.3mm 4 4 TP2 TP2 TP3=18.mm 3 3 1xWL (293 kn) TP3 TP3 TP1=7.5mm 2 2 TP2=6.2mm 1 1 Allowable Allowable Settlement Settlement (CP4) (CP4) TP3=7.4mm 1 1 2 2 3 3 4 4 5 5 6 6 Settlement Settlementat attop Top(mm) (mm) 7 7 8 8 9 9 1 1

JIF, Qtot, Qs, and Qb 1 Qtot Qtot Qtot* 9 8 769 7332 7 6298 (kn) 6 5 8762 (JIF) 593 (JIF) 6617 6353 625 Force (JIF) Qtot 4475 Qs Qb 4 2737 3 2 1392 979 1 TP1', L=28.7m (Failure test) TP2*, L=29.9m TP3, L=31.7m (Non failure test) (Failure test)

Unit Shaft Resistance Vs Displacement Lev A to Lev B Lev B to Lev C 25 Le v A to Lev B ( 1.4 m t o 6.4 m ) N - a ve = 9 2 15 3 TP1 TP1' N - av etp1' = 1 Le v A t o Le v BN -(av1.4 m Lev A t o Le v B e = 11 ( 1.2m to t8o. 4 56m.4m ) ) N - a v etp3 = 9 Le v A t o Le v B ( 1.2 m t o 8. 4 5m ) N - a v e = 11 TP2 TP2 TP3 TP3 1 N -a v e = 7 Le v B t o Le v C ( 6.4m t o 14.9 m ) N - a v e = 1 Le v C ( 6.45 m t o 1 4.2 m) 25 TP2 Le v B t o Le v C t o) (6.4 5 Lev m t o 1B 4.2m Le v B t o Lev C Le v B t o Le v C -a v e ( 6.4m t o 14.9N m) 2 TP1' TP2 N - a v e = 1 =5 TP2 TP2 TP3 ( 8.4 5m t o 15.9 5 m ) Le v B t o Lev C ( 8.4 5m t o 15.9 5m ) 15 N - a ve = 5 1 2 3 4 5 6 7 8 9 TP3 TP3 1 5 1 2 3 4 5 6 7 8 9 15 N -a ve = 25 TP1' 1 N - av e = 16 TP2 5 1 2 3 4 5 6 7 8 9 N -ave = 25 Le v D t o Le v E ( 2.9 m t o 2 4.4 m ) N -ave = 29 Le v D t o Le v E ( 2 2.7 m t o 2 8.2 m ) N - a v e = 16 TP1 TP1' TP2 TP2 TP3 TP3 TP3 TP3 1 2 3 4 5 6 7 8 9 1 7 8 9 1 Lev F to Lev G 25 2 Le v E to Le v F (2 3.2 m to 2 6.2m ) N -a v e = 2 4 Le v E to Le v F (2 4.4 m to 2 7.4m ) N -a v e = 3 Le v E to Le v F (2 8.2 m to 2 9.2m ) N - a ve = 19 TP1' TP2 TP3 15 1 25 2 15 1 5 Lev F to Lev G (2 6.2 m to 2 8.2 m ) N -a v e = 3 5 Lev F to Lev G (2 7.4 m to 2 9.4 m ) N -a v e = 3 5 TP2 Lev F to Lev G ( 2 9.2 m t o 3 1.2 m) N -a v e = 2 9 TP3 TP1' 1 2 3 4 5 6 7 8 9 Displacement (mm) Displacement (mm) Displacement (mm) Displacement (mm) Le v D t o Le v E ( 19.7 m t o 2 3.2 m ) 1 N -ave = 24 3 TP2 TP2 TP3 Displacement (mm) Displacement (mm) 5 TP3 = 24 1 UnitShaft Shaft Resistance (kpa) (kpa) Unit Resistance Unit Shaft Resistance (kpa) Unit Shaft Resistance (kpa) 2 Lev D to Lev E ( 22.7m t o 28.2 m) Le v C t o Le v D ( 15.9 5 m t o 2 2.7 m ) Lev E to Lev F 25 TP2 N -ave = 24 ( 15.9 5 m to 22.7 m ) 15 1 3 N -a ve = 29 Le v C t o Le v D ( 14.9 m t o 2.9 m) Le v C t o Le v D N -a v e 2 TP1' N -a v e = 24 Displacement (mm) Displacement (mm) Lev D to Lev E Lev D to Lev E ( 2.9m t o 24.4 m) Le v C t o Le v D ( 14.9 m to 2.9 m ) 1 Displacement(mm) (mm) Displacement Lev D to Lev E ( 19.7 m to 23.2m ) 25 5 3 TP1 N - a v e =TP1' 11 ( 14.2 m t o 19.7 m ) U nit Shaft R esistan ce (kpa) Le v C t o Le v D N - av e = 11 t om) Le v D ( 14 Le.2 mvt oc19.7 TP1 N - a vetp1' = 7 ShaftResistance Resistance (kpa) UnitUnit Shaft (kpa) N - a ve = 1 Le v B ( 1.7 m t o 6.4 5 m ) Unit Shaft Resistance (kpa) Le v A t o Lev B ( 1.7Le m to.4 5 tmo ) v 6A 5 Unit Shaft Resistance (kpa) Lev C to Lev D 3 Unit Shaft Resistance (kpa) Unit Shaft Resistance (kpa) Unit Shaft Resistance (kpa) 3 Le v E t o Le v F ( 2 3.2 m t o 2 6.2 m ) N -ave = 24 Le v E t o Le v F ( 2 4.4 m t o 2 7.4 m ) N -ave = 3 Le v E t o Le v F ( 2 8.2 m t o 2 9.2 m ) N - a v e = 19 1 1 2 3 4 5 6 Displacement (mm) Displacement (mm) TP1 TP1' TP2 TP2 TP3 TP3 Lev F t o Lev G ( 2 6.2 m t o 2 8.2 m ) N - a ve = 3 5 Lev F t o Lev G ( 2 7.4 m t o 2 9.4 m ) N - a ve = 3 5 Lev F t o Lev G ( 2 9.2 m t o 3 1.2 m ) N - a ve = 2 9 TP1' TP2 TP3

Mobilized Shaft Resistance & End Bearing (Jurong Formation) 1 25 CP-4 Ks= 5N TP2 225 TP1 9 8 UnitU nend it En dbearing B earin g (kpa) (kpa) Unit Shaft Resistance (kpa) Unit Shaft Resistance (kpa) 2 175 15 TP3 125 CP-4 Ks= 2N 1 75 7 6 5 4 3 2 5 TP1' TP2 1 25 TP3 5 1 15 2 25 3 35 4 N-SPT SPT-N SPT-N 45 5 55 6 65 7 75 1 2 3 4 5 6 7 Base Settlement (mm) (mm) PilePile Base Settlement Combined Plot TP1, TP2 and TP3 8 9 1

Preload Effect 23 Rankine Lecture (Prof M.F. Randolph) Bored Pile No residual pressure at pile base during installation End-bearing could only be mobilized at relatively large displacement Jack-In Pile Significant residual pressure at pile base during installation (higher than driven pile) Higher end bearing could be mobilized at small displacement Bored pile Jack-in pile

Conclusions (1) Instrumented load tests have verified that : Qu of pile > Calculated Qu adopted from driven pile Qu of pile > JIF Piles installed by JIF of 1.5~2.25 x WL have adequate Qu & settlement within allowable criteria. Qu of Jack-in pile is a function of JIF and increases as JIF increases. All 3 test piles showed similar load-settlement behaviour up to 2xWL. Higher JIF could result in higher Qu but the use of JIF 1.5xWL is enough to ensure satisfactory pile performance up to 2xWL.

Conclusions (2) JIF > 2xWL could be better but may not be necessarily needed. An appropriate JIF shall be established with the use of static load test. Subsequently all piles could be installed using this termination criteria. Jack-in pile installation results in a preloaded pile toe condition, hence better displacement performance. More future research would help to provide accurate design in the use of jack-in pile.

THANK YOU! CSC HOLDINGS LIMITED

Q & A CSC HOLDINGS LIMITED