Seafco Research Development

40th Anniversary Celebration of Seafco Public Company Limited19 December 2014

40th Anniversary C

elebration of Seafco Public Com

pany Limited

Current Practices in Deep Foundations and Diaphragm

Wall C

onstruction in Thailand

Current Practices in Deep Foundationsand Diaphragm Wall Construction in Thailand

Editors:

Zaw Zaw AyeAung Win MaungThayanan BoonyarakChalermpol TaechakumthornNutthachai ProngmaneeNutthapon Thasnanipan

Seafco Public Company Limited144 Prayasuren Road, Bangchan, Khlong Sam Wah, Bangkok 10510

TEL : (662) 919-0090 - 7, FAX : (662) 919-0098www.seafco.co.th

WE BUILD MODERN FOUNDATIONS2014

Current Practices in Deep Foundations and Diaphragm Wall Construction in Thailand is published to mark the auspicious occasion of SEAFCO 40th Anniversary. It is a compilation of 48 selected published papers in the international conferences. The case studies and researched works presented in these papers are mainly from the projects carried out by SEAFCO in Bangkok and other parts of Thailand. Published papers authored by SEAFCOs geotechnical engineers in other major projects and research studies overseas are also included.

In Thailand, according to the authors experience as a contractor, development in both construction and design aspects of wet-processed deep-seated bored piles, barrette foundations and diaphragm walls in past four decades are significant. With recognition of technical and economic advantages of using these high capacity cast-in-place foundations by local practitioners, it is expected that they will be more popular in the future construction industry of Thailand and the region. However, in the authors opinion, there is much work to be done with particular focus on constructability issues, concrete technology for wet-processed bored piles and barrette, reliable but cost-effective quality control testing and application of value-engineering in design and construction. Starting from the planning stage, site investigation, design, construction and inspection should be integrated to enable designers, contractors and construction inspectors to participate as a team with a common goal. Appropriate and practical specifications should be established jointly by these parties for local soil conditions and construction methods. Continuing education should be promoted for designers, inspection engineers, and contractors.

SEAFCO is committed to continue its research-minded initiation to link theory and practice in deep foundations. We hope that researched works and findings presented in this book will be useful and serve as a source of reference to all in the field of geotechnical and foundation engineering, particularly those who are involved in the construction industry of Thailand.

40th Anniversary Celebration of Seafco Public Company Limited19 December 2014

Current Practices in Deep Foundationsand Diaphragm Wall Construction in Thailand

Editors:

Zaw Zaw AyeAung Win Maung

Thayanan BoonyarakChalermpol Taechakumthorn

Nutthachai ProngmaneeNutthapon Thasnanipan

Member of

PREFACE

Seafco Public Company Limited is a deep foundation contractor established in 1974. The company has been involved in numerous foundation and deep excavation projects in Thailand, including large-scale foundation works, infrastructure projects, and more recently the underground structures of Bangkoks second subway project (MRT Blue Line Extension Project). SEAFCO expanded its operation overseas and successfully took part in the construction of diaphragm walls for Marina Bay Sands in Singapore in 2007. SEAFCO has also established Seafco (Myanmar) Company Limited in late 2013 and completed two projects to date.

Consolidating state-of-the-art technology, sophisticated equipment and engineering professionals, SEAFCO initiated the innovative techniques and solutions in geotechnical and foundation engineering in Thailand and Myanmar. To improve the currently used methods, material, system, design concepts and construction techniques, SEAFCO has spent considerable time and effort on Research and Development activities.

SEAFCOs R&D team continuously conducts research on bored piles, barrettes, diaphragm walls, associated testing methods, deep excavation and other geotechnical engineering works. New findings and research results have been presented in a number of conferences and seminars organized by various institutions both domestically and internationally. In forty years, R & D Division of SEAFCO has produced over 100 technical papers (both in English and Thai) which were presented and published in international conferences held in various countries. The purpose of this publication is to mark the auspicious occasion of SEAFCO 40th Anniversary. It is a compilation of selected published papers in the international conferences. The case studies and research works presented in these papers are mainly from the projects carried out by SEAFCO in Bangkok and other parts of Thailand. Published papers authored by SEAFCOs employees in other major projects and research studies overseas are also included.

I would like express my appreciation to the clients, consultants, designers, universities, institutions, the Engineering Institute of Thailand under H.M. the Kings Patronage (EIT) and partners who have been continuously supporting SEAFCO for 40 years. I also would like to acknowledge the effort of SEAFCOs R&D team for their commitment and hard work in the research works.

I hope that researched works and findings contained in these publications will be useful and serve as a source of reference to all in the field of geotechnical and foundation engineering, particularly those who are involved in the construction industry of Thailand.

Narong ThasnanipanPresident & CEOSeafco Public Company Limited

FOREWORD

First of all, I would like to extend my congratulations to SEAFCO for 40 years of successful establishment, not only as a business entity but also as a great contributor for construction industry of Thailand.

SEAFCO is well known for research minded initiatives in foundation engineering. SEAFCO shares outcomes of its R&D works to the engineering society by publishing technical papers, organizing conferences, and delivering lectures in various institutions in both Thailand and overseas. I proudly acknowledge the contributions SEAFCO has been making to strengthen the foundation of civil engineering society in Thailand and beyond.

Since the time I was working on my doctoral research, I have found SEAFCOs publications in various international conferences very useful to understand practical aspects of deep foundations. SEAFCO puts the innovative theory into practice by equipping itself with knowledge, experience and professionalism. SEAFCO R&D team has put in commendable effort to compile all of their published papers and produced the book Current Practices in Deep Foundations and Diaphragm Wall Construction in Thailand. Geotechnical specialists, foundation engineers, structural engineers and practitioners in construction industry will find this book beneficial.

I, as the President of the Engineering Institute of Thailand under H.M. The Kings Patronage (EIT), would like to sincerely thank Seafco Public Company Limited for endless support they have been providing to the various activities of EIT under the leadership of CEO Khun Narong Thasnanipan. In particular, SEAFCOs great support in a leading role to Thailand Underground & Tunneling Group (TUTG) in winning the bid for Thailand to host the World Tunnel Congress 2012 and successfully organizing the event at Queen Sirikit National Convention Center in Bangkok from 18 to 23 May 2012.

I believe SEAFCO will continue to grow in business with trust and confidence of its stakeholders. I am also confident that SEAFCO will maintain its position as the leading innovators of foundation and geotechnical engineering.

I wish SEAFCO all the success.

Prof. Dr. Suchatvee Suwansawat

President

The Engineering Institute of Thailand

Table of Contents

Bored Pile and Barrette: Construction Methods, Design, Analysis and Performance

Barrettes Founded in Bangkok Subsoils, Construction and Performance Thasnanipan N., Maung A.W. & Tanseng P. .................................................................. 1

Design, Construction and Behavior of Bored Cast In-Situ Concrete Piles in Bangkok Subsoil Thasnanipan N., Teparaksa W., Maung A.W. & Ganeshan B. ........................................ 9

Large Diameter Bored Piles in Multi-Layered Soils of BangkokThasnanipan N., Tanseng P. & Anwar M.A. .................................................................. 19

Effect of Construction Time and Bentonite Viscosity on Shaft Capacity of Bored Piles Thasnanipan N., Ganeshan B. & Anwar M.A. .............................................................. 29

Performance Comparison of Bored and Excavated Piles in the Layered Soilsof Bangkok Thasnanipan N., Anwar M. A., Maung A.W. & Tanseng P. .......................................... 39

Base grouting of wet process bored piles in Bangkok subsoilsTeparaksa W., Thasnanipan N. & Anwar M. A. ............................................................. 51

Review of the Shaft Capacity Degradation of Bored Piles Constructedwith Bentonite SlurryThasnanipan N., Anwar, M. A. & Maung A. W. ............................................................. 57

Failure Mechanism of Long Bored Piles in Layered Soils of Bangkok Thasnanipan N., Anwar, M. A. & Maung A. W. ............................................................ 69

Barrettes : A Versatile Foundation for Transmission Line Towers Thasnanipan N., Tanseng P., Maung A.W. & Anwar M. A. ............................................ 77

Practical Installation of Stanchions for Top-Down Construction in Bangkok SubsoilThasnanipan N., Maung A. W. & Z. Z. Aye ................................................................... 85

Concrete for Wet Process Bored Piles Thasnanipan N., Maung A. W., Tanseng P. & Navaneethan T. .................................... 97

Record Load Test on a Large Barrette and its Performance in the layeredsoils of Bangkok Thasnanipan N., Maung A. W. & Z. Z. Aye ................................................................. 107

Performance of Wet-Process Bored Piles Constructed with Polymer-Based Slurry in Bangkok SubsoilThasnanipan N., Z. Z. Aye, Submaneewong C. & Teparaksa W. ............................... 117

Barrette of Over 50,000 kN Ultimate Capacity Constructed in the Multi-Layered Soil of BangkokThasnanipan N., Z. Z. Aye & Teparaksa W. ................................................................ 135

Performance of Toe-grouted Large Bored Piles in Sand-Gravel

Formation of Chiang Mai City, Northern Thailand Thasnanipan N., Z. Z. Aye & Teparaksa W. ................................................................ 145

Application of Polymer-based Slurry for Wet-process Bored PilesConstruction in Mylti-layered Soil of Bangkok Z. Z. Aye, Singtogaw K. & Submaneewong C. ........................................................... 155

Development in Construction of Bored pile and Barrette for Infrastructure Projects in Thailand, A Country Report Thasnanipan N., Singtogaw K., Z. Z. Aye & Pravesvararat S. .................................... 163

Behaviour of Polymer-based Slurry for Deep-seated Bored Piles in Multi-layered Soil of Bangkok Thasnanipan N., Z. Z. Aye & Boonyarak T. ................................................................. 175

Effectiveness of Toe-Grouting for Deep-Seated Bored Piles in Bangkok Subsoil Thasnanipan N., Z. Z. Aye & Submaneewong C. ....................................................... 185

Current Practice and Future Trends of Cast-in-place Deep Foundation in Thailand Thasnanipan N., Singtogaw K., Z. Z. Aye & Pravesvararat S. ................................... 199

Development and Achievement of Deep-seated Bored Piles and Barrettes Construction in Thailand in the Past Forty Years, A Country ReportThasnanipan N., Z. Z. Aye, Submaneewong C. & Boonyarak T. ................................. 211

Barrette for High-rise Buildings and Heavy Structures in Bangkok Sub-soil Thasnanipan N., Z. Z. Aye, Boonyarak T., Kitpayuck P. & Thasnanipan N. ...................................................................................................... 223

Diaphragm Wall and Deep Excavation

Performance of a Braced Excavation in Bangkok Clay, Diaphragm WallSubject to Unbalanced Loading ConditionsThasnanipan N., Maung A.W., Tanseng P. & Wei S.H. ............................................... 245

Prediction and Performances of Short Embedded Cast In-Situ DiaphragmWall for Deep Excavation in BangkokThasnanipan N., Teparaksa W., Maung A.W. & Wei S.H. ............................................ 253

Lessons from the collapse during construction of an inlet pumping station: Geotechnical instrumentation aspectTeparaksa W., Thasnanipan N., Maung A. W. & Tanseng P. ....................................... 263

Behavior and performance of diaphragm walls under unbalanced lateral loading along the Chao Phraya River, Thasnanipan N., Maung A. W. and Tanseng P. & Teparaksa W. ............................... 271

Analysis of Lateral Wall Movement for Deep Braced Excavation of Bangkok SubsoilsTeparaksa W., Thasananipan N., & Tanseng P. ....................................................... 279

Diaphragm Wall and Barrette Construction for Thiam Ruam Mit Station Box,MRT Chaloem Ratchamongkhon Line, BangkokThasnanipan N., Maung A.W. & Ganeshan B. ............................................................. 291

Monitoring of Diaphragm Wall Displacement and Associated GroundMovement, Braced Excavation Adjacent to Historical Building at the Bankof Chao Phraya RiverTanseng P., Z. Z. Aye & Submaneewong C. ............................................................... 299

Performance of Buttress-Support Thin Diaphragm Wall for UndergroundCar Park in Bangkok Thasnanipan N., Z. Z. Aye & Submaneewong C. ........................................................ 309

Stability of a Trial Trench Excavated under Polymer Slurry in Bangkok Soft Clay Thasnanipan N., Maung A. W., Boonyarak T. & Aye, Z. Z. .......................................... 315

Application of Top-down Construction Method for Deep Excavations in Urban Area of BangkokThasnanipan N., Z. Z. Aye, Submaneewong C. & Boonyarak T. ................................. 321

Construction of diaphragm wall for basement excavation adjacent to tunnels in Bangkok subsoilThansnanipan N., Maung A. W., Z. Z. Aye, Submaneewong C. & Boonyarak T. ........................................................................................................... 337

Application of Observational Method in Diaphragm Wall Support Basement ExcavationZ. Z. Aye, Submaneewong C., Boonyarak T. & Chanchad C. ...................................... 351

Diaphragm Wall Support Deep Excavation in BangkokThasnanipan N., Z. Z. Aye, Maung A. W. Boonyarak T., Kitpayuck P.&Thasnanipan N. ........................................................................................................... 369

Underpass Construction in Congestive Area of BangkokZ. Z. Aye, Boonyarak T., Kitpayuck P., Mahasantipiya S. & Thasnanipan N. ...................... 387

Quality Control Tests on Deep Foundations

Sonic Integrity Test on Piles Founded in Bangkok Subsoil-Signal

Characteristics and Their Interpretations

Thasnanipan N., Maung A.W. & Ganeshan B. ........................................................... 405

Sonic Integrity Test of Piles-integrity Effected by Basement Excavation

in Bangkok Soft Clay

Thasnanipan N., Maung A. W., Tanseng P. & Z. Z. Aye ............................................. 415

Non-Destructive Integrity Testing on Piles Founded in Bangkok Subsoil

Thasnanipan N., Maung A. W. & Navaneethan T. & Z. Z. Aye ..................................... 425

Damages to Piles associated with Excavation Works in Bangkok Soft Clay

Thasnanipan T., Maung A. W. & Tanseng P. ............................................................... 435

Quantifying Pile Head Condition Before Basement Excavation by

Cross-hole Sonic Logging Tests

Thasnanipan N., Z. Z. Aye, Boonyarak T. & Kampananon N. ...................................... 445

Advantages and Limitations of Integrity Tests for Large Diameter Bored

Piles in Bangkok

Thasnanipan N., Z. Z. Aye, Boonyarak T. & Kampananon N. ...................................... 453

Application of Low-strain Integrity Tests for Quality Assurance of

Deep Foundations in Thailand

Maung A. W., Z. Z. Aye & Boonyarak T. ...................................................................... 463

Geotechnical Engineering : Research and Practice

Ground Movement Prediction and Building Damage Risk-Assessment

for the Deep Excavations and Tunneling Works in Bangkok Subsoil

Z. Z. Aye, Karki D. & Schulz C. ................................................................................... 473

Key Factors in Application of Observational Method Bangkok Experience

Phienwej N. & Z. Z. Aye ........................................... ................................................... 495

Ground Movements Associated with the Underground Excavations

of the First Bangkok MRT Line

Phienwej N., Sirivachiraporn A., Suwansawat S. & Z. Z. Aye ...................................... 525

Geotechnical Risk Assessment and Management for Tunnelling Project

in Congestive Urban Area Bangkok Experience

Z. Z. Aye, Kitpayuck P. & Phienwej N. ......................................................................... 535

Tunneling Effect on Pile Group Response in Bangkok

Boonyarak T. & Ng C. W. W. ....................................................................................... 547

A - 13

SEAFCO PUBLIC CO LTD

SEAFCO

DE

EP

FO

UN

DA

TIO

NS

MEMBER OF

Barrettes Strip Piles

When single pile safe working load in excess of 2000 tons is required or conventional bored piling is impractical, barrettes or strip piles are the best al-ternative. Various dimen-sions, cross-sections and orientation can be formed and arranged to suit de-sign requirements. SEAFCO barrettes are used in foundations for ex-pressways, MRTA stations and high-rise buildings.

A - 14

A - 15

A - 16

A - 17

A - 18

PILE BASE GROUTING IN BANGKOK SUBSOILS

Cast-in-situ bored piles with base grouting are in common use in Bangkok for foundations of heavy structures. Base grouting is usually employed in bored piles to improve pile capacity and performance. The unavoidable problems arising from loosening of soil and sedimentation at the base caused by boring can be minimized by base grouting. The first base grouted bored pile in Bangkok was used in 1985 at the Rama IX cable-stayed bridge across the Chao Phraya River.

Teparaksa, W. (1994) reported that base grouted piles in the second sand layer of Bangkok subsoils have an increment in their perform-ance as below;

SEAFCO

GROUTING CRITERIA

Grout Pressures: Max imum pressure developed is a single most important parameter. It should be gradually achieved by low injection rates to avoid hy-draulic fracturing.

Grout Volumes: U s u a l l y total grout take is not a limiting criteria and is used to decide about the staged grouting. Gen-erally, the higher the required maximum pressure to be achieved, the higher will be the grout volume under similar condi-

26/10 Prayasuren Road, Bangchan, Khlong Sam Wah, Bangkok 10510. Tel. (662) 919 0090-4, Fax. (662) 919 0098

PERFORMANCE OF BASE GROUTED PILES

Base grouting with tube-a-manchettes technique has been used by SEAFCO in many pro-jects in Bangkok. Improve-ments achieved have been proved by load tests on both non-grouted and base-grouted bored piles on the same project sites.

N on-G route d v s. B ase -G route d Pile s (Silom)

0

10

20

30

40

50

60

0 500 1000 1500 2000 2500 3000 3500 4000

Load (ton)

Settl

emen

t (m

m)

N on-Grou ted Pile - D ia . 1 .5x60 .00mBas e-Grou ted Pile A - D ia .1 .5x55 .16m (3 S tages - to ta l 2000 ltr)Bas e-Grou ted Pile B - D ia .1 .5x60 .00m (3 S tages - to ta l 2000 ltr)

Conditions Increment %

In Failure Load 12-24 In Skin Friction 9-27 In End Bearing 11-21

The above increments were deter-mined at fully mobilized skin friction 1.59-1.86% and 1.04% of pile di-ameter for base grouted and non-base grouted piles respectively.

Mechanism of improvement by base grouting involves; Replacement of sediments with

grout under the pile base. Squeezing water out of the

sediments. Improving the sand stratum

around the pile base. Prestressing of the pile. Increasing skin friction in sand

layers.

GROUTING ASSEMBLY

Current base grouting practice uses two U-circuits consisting of 12mm diameter PE tubes at-tached at the bottom with 12mm GI pipes with perforations wrapped with rubber sleeves (manchettes). They are attached with the reinforcement cage to place the manchettes at the base of the pile.

Injection Rates: It is not a direct controlling parameter but instead used to achieve maxi-mum pressure in a gradual manner. Injection rates of 5-10litres/min are proved to be satisfactory.

Residual Pressures: Normally residual pressures of the order of 20-30% of target maximum pressure are desirable.

N B B-10 G G G Soft Clay

A BStiff Clay

-20Silty Clay

-30

Dense Sand

-40Hard Clay

-50

Dense Sand

-60

A - 19

26/10 Prayasuren Road, Bangchan, Khlong Sam Wah, Bangkok 10510. Tel. (662) 919 0090-4, Fax. (662) 919 0098

SEAFCO

References: Teparaksa, W., Thasnanipan, N. and Anwar M. A. (1999), Base Grouting of Wet Process Bored Piles in Bangkok

Subsoils, Eleventh Asian Regional Conference, International Society for Soil Mechanics and Geotechnical Engineer-ing, Seoul, Korea, August 16-20, 1999. Pp. 269-272.

Lui, J. and Gao W. S. (1999), The Behavior of Post-grouting Pile Groups under Vertical Load, Eleventh Asian Re-gional Conference, International Society for Soil Mechanics and Geotechnical Engineering, Seoul, Korea, August 16-20, 1999. Pp. 209-212.

Thasnanipan, N. (1997), Current Development of Bored Piling Techniques in Bangkok (in Thai), Technical Seminar on Foundation 1997 organized by the Engineering Institute of Thailand, Bangkok, Thailand, February 4, 1997. Pp. 1-26.

Teparaksa, W. (1992), Behavior of Base-Grouted Bored Piles in Bangkok Subsoils, Piling: European Practice and Worldwide Trends. Conference organized by the Institution of Civil Engineers, London, April 7-9, 1992, Thomas Tel-ford. Pp. 296-301.

All rights reserved. No part of this publication may be reproduced in any form or by any means, without the prior written permission of SEAFCO CO., LTD.

Base-Grouted Piles - CP

0

10

20

30

40

0 500 1000 1500 2000

Load (ton)

Settl

emen

t (m

m)

Base-Grouted Pile - Dia. 1.2x55.87m (Grouted Soil)

Base-Grouted Pile - Dia. 1.2x55.90m (Virgin Soil)

Soft Clay

-10 Clayey Sand

Stiff Clay

-20

Silty Clay

-30

Sand

-40 Silty Clay

Silty Clay

-50Dense Sand

-60Silty Clay

Generally, total volume of grout at pile base ranged from 500 liters to 4000 liters at single or multiple stage grouting. Grouting pressure ranges from 25 bars to 60 bars depending on the depth of pile base level and relative density of sand layer in the project area.

Non-Grouted vs. Base-Grouted (Silom) - JTC

0

10

20

30

40

50

60

0 500 1000 1500 2000 2500 3000 3500

Load (ton)

Settl

emen

t (m

m)

Non-Grouted Pile - Dia. 1.5x63.72mBase-Grouted Pile - Dia. 1.5x63.72m (2 Stages - total 1000 ltr)

Age: 60 days

Age: 115 days

Soft Clay

-10

Stiff Clay-20

Dense Sand-30

-40

Desne Sand

-50

Silty Clay

-60Dense Sand

Soft Clay

-10

Stiff Clay

-20

-30

Hard Clay-40

-50

Sand-60

Sandy Clay

Non-Grouted vs. Base-G routed (Prathu-Nam)

0

10

20

30

40

50

60

70

80

0 500 1000 1500 2000 2500 3000

Load (ton)

Settl

emen

t (m

m)

Non-Grou ted Pile - Dia. 1.5x60.2m

Bas e-Grouted Pile - Dia. 1.5x59.72m (2 Stages - to tal 1500 ltr)

Age: 61 days

Age: 57 days

Non-Grouted vs. Base-Grouted (V-Rangsit) -CNW

0

10

20

30

0 500 1000 1500 2000 2500 3000 3500

Load (ton)

Settl

emen

t (m

m)

Non-Grouted Pile - Dia. 1.5x60.2mBase-Grouted Pile - Dia. 1.5x60.3m (2 Stages - total 1500 ltr)

Age: 82 days

Age: 62 days

Soft Clay

-10

Stiff Clay

-20

-30

Hard Clay-40

-50

Sand-60

Sandy Clay

Non-Grouted vs. Base-Grouted Piles (Rama III)

0

10

20

30

40

0 500 1000 1500

Load (ton)

Settl

emen

t (m

m)

Non-Grouted Pile - Dia. 1.0x53.0mBase-Grouted Pile - Dia. 1.0x55.0m (500 ltr 1 Stage)

Soft Clay

-10 N BG G

Stiff Clay-20

-30

Hard Clay-40

-50

Dense Sand

-60 Silty Clay

load settlement curves of base-grouted piles, before and after all adjacent piles have been base-grouted.

A - 20

Object Contiguous bored pile wall and bored piles for con-struction of basement and foundation of the Rama Thibodi Hospital.

Project Description Bored pile wall with temporary braced excavation method for construction of 3 level basements for car parking.

Type of Work Foundation Piling, Contiguous bored pile wall.

Owner Rama VI Hospital.

Designer Arun Chaiseri Consulting Engineers Co., Ltd.

Main Contractor Ch. Karnchang Public Company Limited.

Project Schedule 2005-2006

Construction Method Excavation with contiguous pile wall using bot-

tom up construction method to 11.5m.

Construction Details Foundation bored pile: 7 (0.8mx55m)

121 (1.0mx55m) 163 (1.2mx55m) 32 (1.5mx55m)

Contiguous Pile Wall: 364 (1.0mx20.0m)

Subsoil Conditions Soft clay: 0.0-11.0m Medium clay: 11.0-14.0m Stiff clay: 14.0-28.0m Dense sand: 28.0-30.0m Hard clay: 30.0-47.0m Very dense sand: 47.0-55.0m

Exposed contiguous bored pile wall.

Layout of contiguous and foundation bored piles.

Excavation with braced pile wall for construction of footings and basements.

No. 144, Prayasuren Road, Bangchan, Khlong Sam Wah, Bagkok 10510, Thailand. Tel. (662) 919-0090 to 97, Fax. (662) 919-0098, 518-3088. Email: [email protected], Homepage: www.seafco.co.th.

A - 21

MahaNakhon Deep Foundation Works

Project Description Barrettes, bored piles and diaphragm walls for a 75 storey high-end Hotel and Residence Tower with 2 level basements, and a retail complex with 4 level basements, located on Narathiwas Road.

Type of Work Foundation piling and diaphragm walling.

Owner Pace Project One Co., Ltd., Pace Project Two Co., Ltd. and Pace Project Three Co., Ltd.


Construction Details Foundation bored pile: 0.80mx57-65m = 59 +11 1.00mx57-65m = 13+14 1.20mx65.0m = 4 0.80mx3.0mx65.0m = 1 1.20mx3.0mx65.0m = 114 Diaphragm Walls: 9,264sqm (0.6m to 0.8m thick x 16.0m to 22.0m)

Subsoil Conditions Soft clay: 2.0-8.0m Medium clay: 8.0-13.0m Stiff clay: 13.0-24.0m Dense sand: 24.0-38.8m Hard clay: 38.8-43.0m Very dense sand: 43.0-49.1m Hard Clay: 49.1-55.0m Very Dense Sand 55.0-67.0m

Rebar Cage Installation for Diaphragm Wall.

Layout of the project.

General View of the Site.


Diaphragm Wall Construction in Progress.

A - 22

Object Construction of basement structures of a 42 storey office tower on 9 storey retail podium.

Project Description Construction of bored pile foundations, diaphragm walls and deep excavation works for 2-3 level base-ments construction.

Type of Work Foundation piling, diaphragm walling and substruc-ture works.

Owner Land and House Property Company Limited.

Designer Palmer &Turner (Thailand) Limited.


Construction Method Bored piling and diaphragm walling Deep excavation to 13.0m with diaphragm

walls using bottom up construction method. Construction Details Foundation bored pile: 0.80mx57m = 22 1.20mx57m = 65 1.50mx57m = 183 1.80mx57m = 25 Diaphragm Walls; 8,172 sq.m. (0.80m thick x 18m deep) Voume of Excavation: 95,000 cu.m. Temporary Bracing: 1,987 tons Temporary Platform: 3,807 sq.m. Concrete Volume: 24,295 cu.m. (substructure) Steel Reinforcement: 4,350 tons (substructure) Basement Floor: 30,909 sq.m.

Subsoil Conditions Soft clay: 2.5-9.0m Medium clay: 9.0-15.3m Stiff to very stiff clay: 15.3-40.0m Hard clay: 40.0-42.8m Dense Sand: 42.8-60.0m

Completed substructure.


Excavation with braced diaphragm wall for construction of basements.


A - 23

ASOKE COMPLEX - INTERCHANGE TOWER

Substructure Works

ObjectConstruction of foundation mats, footings, deep base-ments for car parking and wastewater treatment tanks.

Project Description Diaphragm wall with 2-3 levels temporary bracing for deep excavation up to 15.90m to construct 3.5 level basements for car parking.

Type of Work Deep excavation with temporary bracing, Civil Con-struction.

OwnerB&G Park Company Limited.

DesignerPalmer and Turner (Thailand) Ltd.

Project Schedule March 2005 November 2006

Construction Method Braced excavation to 15.90m with diaphragm

wall using bottom up construction method.

Construction Details Temporary bracing: 1,478 tons Earth excavation: 54,000cu.m Basement floor area: 13,000sq.m.

Subsoil Conditions Soft clay: 0.0-14.0mMedium clay: 14.0-15.0m Stiff clay: 15.0-24.0m Hard clay: 24.0-40.0m Very dense sand: 40.0m+

Concrete casting of 3.0m thick foundation mat in progress.

Layout of temporary bracing.

Rebar fixing for foundation mat in progress.

144, Prayasuren Road, Bangchan, Khlong Sam Wah, Bagkok 10510, Thailand. Tel. (662) 919-0090 to 97, Fax. (662) 919-0098, 518-3088. Email: [email protected], Homepage: www.seafco.co.th.

A - 24

UBC III AND EM2

Deep Foundation Works

Project Description Bored piles and diaphragm walls for a 32 storey office tower and shopping complex with 2 to 4 level basements, located on Sukhumvit Road.

Type of Work Foundation piling and diaphragm walling.

Owner Bhiraj Buri Co., Ltd (UBC III) & Sukhumvit City Mall Co., Ltd. (EM2)

Project Schedule 2011

Construction Details Foundation bored pile: 0.60mx18.5m = 126 Bored Pile Wall 0.60mx22-23.0m = 433 Bored Pile Wall 0.80mx18.5m = 393 Foundation bored pile: 0.80mx60.0m = 158 1.00mx60.0m = 30 1.20mx60.0m = 27 1.50mx60.0m = 308 1.80mx60.0m = 140 0.80mx3.00mx60.0m = 4 1.00mx3.00mx60.0m = 22 Diaphragm Walls: 7,057.5 sqm (0.8-1.0m thick x18.0-22.0m)

Subsoil Conditions Soft clay: 1.5-13.5m Medium clay: 13.5-16.3m Stiff clay: 16.3-32.5m Dense sand: 32.5-34.0m Hard clay: 34.0-53.9m Dense Sand: 53.9-58.0m

Drilling for Large Diameter Bored Piles.


General View of the Site.


Diaphragm Wall Construction in Progress.

A - 25

Object Construction of a 2 level underground car park under a football field.

Project Description Construction of bored pile foundations, diaphragm walls and deep excavation works for 2 level base-ments and football field on top.

Owner Srinakrin Wiroj University

Architects & Engineers Krunthep Tanakom Co., Ltd. (Designer) Plan Consultants Co., Ltd. Kumjornkit Construction Co., Ltd. (MC)


Construction Method Bored piling and diaphragm walling Deep excavation to 7.3m with diaphragm

walls using top-down construction method

Construction Details Foundation bored pile: 0.60mx18.5m = 508 Diaphragm walls; 7,664 sq.m. (0.60m thick

x 16m deep) Excavation volume: 102,000 cu.m Basement floor: 36,000 sqm Concrete volume: 39,624 cu.m Reinforcement: 4,218 tons

Subsoil Conditions Soft clay: 2.0-14.5m Medium clay: 14.5-17.0m Stiff clay: 17.0-22.0m Hard clay: 22.0-41.5m Sand: 41.5-46.0m Hard clay: 46.0-49.0m Dense sand: 49.0-60.0m

Substructure works in progress.

Layout of the project (Courtesy of the Designer)

Excavation with diaphragm wall using top-down construction method for base-ment construction.


A - 26

Object Deep foundation work for wastewater treatment plant.

Project Description Bored piles and diaphragm walls for construction of deep basements for a wastewater treatment plant in Bangsu, Jatujak area.

Type of Work Foundation piling, diaphragm walling and soil im-provement.

Owner The Bangkok Metropolitan Administration.

Designer & Engineers The Bangkok Metropolitan Administration. CH. Karnchang Public Company Limited (MC)


Construction Details Foundation bored pile: 0.80mx57.0m= 971 1.00mx57.0m = 7 1.00mx57.0m = 380 1.50mx57.0m = 46 Diaphragm Walls: 2,460 sq.m (1.5m thick x 24.7m deep ) 10,225 sq.m (1.2m thick x 24.7m deep ) Soil mixing: 1,734 cu.m

Subsoil Conditions Soft clay: 2.0-10.0m Medium clay: 10.0-13.5m Stiff to very stiff clay: 13.5-24.0m Dense sand: 24.0-60.0m

Diaphragm wall and bored pile construction in progress.

Layout of pile foundation and diaphragm walls.

Birds eye view of the project site.


A - 27

Object Underground car park with disable access, natural light and ventilation for the Central Hospital of Bang-kok Metropolitan Authority. Large open space and garden on the roof top.

Project Description Diaphragm wall with top down excavation method for construction of 4 level basements for car parking and roof top garden.

Type of Work Foundation Piling, Diaphragm Walling, Deep Excava-tion, Civil Construction.

Owner & Designer The Bangkok Metropolitan Administration


Construction Method Excavation with diaphragm Wall using top-

down construction method to 13.0m.

Construction Details Foundation bored pile: 69 (1.8mx22m) Diaphragm Wall: 4,900sq.m. (0.8m thick, 20.0m deep) Basement floor area: 11,200sq.m. Landscaping: 2,800sq.m.

Subsoil Conditions Soft clay: 0.0-11.0m Medium clay: 11.0-14.0m Stiff clay: 14.0-30.0m Dense sand: 30.0-37.0m Hard clay: 37.0-42.0m Very dense sand: 42.0-50.0m

Diaphragm wall and bored pile construction.

Excavation with permanent RC beams lateral support in progress.


Cross section of underground car park.

Birds eye view of the completed underground car park.

A - 28

Object Deep foundation works for a 47 storey luxury condo-minium.

Project Description Bored piles, contiguous pile wall, diaphragm walls and soil improvement for construction of deep base-ment.

Owner Sathorn Park Co., Ltd. & Grace Ivory Co., Ltd.

Designer Meinhardt (Thailand) Ltd. (Structural Engineers)


Construction Details Foundation bored piles: 1.00mx55.0m = 192 1.20mx55.0m = 238 Contiguous bored pile: 1.00mx22.0m = 83 Diaphragm Walls: 6,352 sq.m. (1.0m thick x 20-22.0m deep) 1,377 sq.m. (1.2m thick x 20-22.0m deep) Soil mixing: 275 cu.m.

Subsoil Conditions Soft clay: 2.5-10.0m Medium clay: 10.0-16.0m Stiff clay: 16.0-26.0m Dense sand: 26.0-60.0m

Diaphragm wall construction in progress

Layout of pile foundation and diaphragm walls.

Bored piling in progress.


Exposed diaphragm wall and contiguous piles.

A - 29

SRINAKRIN UNDERPASS

Civil Works

Project Description Construction of an underpass for the traffics along Srinakrin Road.

Type of Work Foundation piling, diaphragm walling and civil works.

Owner The Bangkok Metropolitan Administration (BMA).


Construction Details Foundation bored pile: 1.00mx29.0m = 73 0.80mx3.0x25.0m = 3 Diaphragm Walls: 13,672sqm (0.8m thick x 25.0m)

Structural Concrete: 42,230cu.m Reinforcement Steel: 5,266tons

Subsoil Conditions Soft clay: 3.0-15.0m Medium clay: 15.0-18.0m Stiff clay: 18.0-19.5m Hard clay: 19.5-25.0m

Construction of the Underpass in Progress.

Construction of Diaphragm Wall under the Existing Highway.


Layout of the Project.

A - 30

GENERAL

Thiam Ruam Mit (Thailand Cul-tural Center) Station (S12) is one of 18 underground stations of the Metropolitan Rapid Transit Au-thority (MRTA) Initial System Pro-ject. The station is located on Ratchadapisek Road. The initial system project or Blue Line is the first link in the network and 20km. Long. The perimeter walls of the station box are made of cast in-situ concrete diaphragm walls 1.0m and 1.2m thick. The south wall of the station is a 1.2m thick diaphragm wall and has openings for three tunnels linking the south and north underground stations to the Depot. A Tunnel Boring Machine (TBM) driving shaft for twin tunnels is also included in the station box on the northern end.

Diaphragm walls are embedded 32-35m deep in sand layer for 24.5m deep excavation work. 63 barrettes (1.2mx3.0m) embedded 44.5-55.0m deep in conjunction with pre-placed steel stanchions at the top are used to facilitate top down construction and to support the station box.

Glass Fibre Polymer Reinforce-ment was used in diaphragm wall panels at the tunnel opening lo-cations to allow direct break through for TBM.

BMA System (BTS)SRT System (Hopewell)

MRTA Interchange StationMRTA ISP (Underground Structures-South)MRTA ISP (Underground Structures-North)

MRTA Station

LEGEND :

CHAO

PHRA

YARI

VER

THIAM RUAM MIT STATION

BANG SU STATION

HUA LAMPHONG STATION

WORK UNDERTAKEN BORED PILES: Dia. 0.6mx19.5-23.5m 12 nos. Dia. 1.0mx36.0m 95 nos. Dia. 1.2mx36.0m 9 nos. Dia. 1.5mx36.0m 5 nos. BARRETTES: 1.2mX3.0mX44.5-55.0m 63 nos. STEEL STANCHION: 859 tons DIAPHRAGM WALL: 24,338.9 sq.m. (1.0m Thick) 1,612.8 sq.m. (1.2m Thick)

LC TRACKC TRACKL

DIAPHRAGM WALL

TOP SLAB

CONCOURSE SLAB

ORANGE LINE PLATFORM

ORANGE LINE SLAB

BASE SLAB

20.2520.25 6.03 6.03

+101.000Foot Path

Stiff Clay

Soft Clay

Silty SandBARRETTE

+80.450

+98.900

+78.450

TYPE OF WORK: Foundation Piles, Diaphragm Wall and BarrettesOWNER: The Metropolitan Rapid Transit AuthorityMAIN CONTRACTOR: Nishimatsu Construction Co., Ltd. (ION Joint Venture)DESIGNER: Ove Arup and Partners International LimitedPERIOD: 1998-1999 SEAFCO

144 Prayasuren Road, Bangchan, Khlong Sam Wah, Bangkok 10510. Tel. (662) 919 0090-7, Fax. (662) 919 0098

Location of Thiam Ruam Mit Station.

Cross section of station box (Schematic).

D04

/99

A - 31

Lowering a reinforcement cage with glass fibre polymer reinforcement soft eye for tunnel opening.

Exposed diaphragm wall in-side (TBM) driving shaft.

Subsoil conditions at the site.

RATCHADAPHISEK RD.

TO RAMA IXROAD

OPENAREA

LC

L

LC

C

4-CF

OR

AN

GE

LIN

E

CL

4-CF

TO LATPHRAOROAD

R.S.TOWER

CL

LC

N THAIINSURANCE

Mr. P FRESH MILK

2-SC 2-SC

2-SC

2-SC2-SC

ENTRANCE12.1

ENTRANCE12.4

VENT.SHAFT1

ENTRANCE12.2

ENTRANCE12.3

SHAFT2

VENT.

359.500

27.000TBM

DRIVESHAFT

S P T

-70

-60

-50

-40

-30

-20

-10

00 2 0 40 6 0 8 0

N (B lo w s /ft)

Dep

th (m

)

B H -2B H -3B H -37

U n d ra in ed S h ear S tren g th

-70

-60

-50

-40

-30

-20

-10

00 5 10 15

S u (t/m 2)

Dep

th (m

)

B H -3F IL L

S O F T C L A Y

S T IF F C L A Y

M E D IU M D E N S E S A N D

H A R D C L A Y

Layout of station, diaphragm wall and barrettes.

Panel excavation with grab.

Concrete pouring using double tremie sets for T-Shaped panel.

A large volume of bentonite slurry sup-ply, storage and treatment facilities for an excavation up to 300 cu.m.

General view of the site (diaphragm wall and barrette work).

Placing a strip of water-stop in the stop-end plate.

A wall panel being cast with a wa-ter-stop between panel joints.

A - 32

Concreting a barrette with pre-placed steel stan-chion, using double tremie sets .

Barrette construction in progress (SEAFCO Guide Frame with extended section to control verticality of stanchion in the foreground)

Steel stanchions on site, ready to be installed.

A scene of barrette construction activity.

Verticality of stanchion can also be checked against tall buildings nearby.

Left Lowering rebar cage at-tached with sonic logging access tubes.

Centre Setting up SEAFCO guide frame for steel stanchion to be installed with great accu-racy.

Right Placing a steel stanchion in position.

A - 33

SEAFCO

References Teparaksa, W., Thasnanipan, N., Maung, A. W. and Wei, S. H. (1998), Prediction and Performances of Short Em-

bedded Cast In-situ Diaphragm Wall for Deep Excavation in Bangkok Subsoil, Fourth International Conference on Case Histories in Geotechnical Engineering, St. Louis, Missouri, March 9-12, 1998. Pp. 686-692.

Thasnanipan, N., Anwar, M., A., Maung, A. W. and Tanseng, P. (1999), Performance Comparison of Bored and Excavated Piles in the Layered Soils of Bangkok, Symposium on Innovative Solutions in Structural and Geotechnical Engineering in Honor of Professor Seng-Lip Lee, AIT, Bangkok, May 14-15, 1999. Pp. 345-353.


Checking trench verticality and dimen-sion with Koden drilling monitoring equipment..

A jack-out pressure cell to be installed in the reinforcement cage of diaphragm wall.

Attaching a vibrating wire strain gauge in the reinforcement cage of diaphragm wall.

Checking concrete quality of barrette with sonic logging method. Testing on barrette capacity with fully

instrumented load test.

Sonic logging test record show-ing good quality of concrete .

Drilling monitoring record showing good verticality of trench and dimensions.

All rights reserved. No part of this publica-tion may be reproduced in any form or by any means, without the prior written per-mission of SEAFCO PUBLIC CO., LTD.

Monitoring and Checking Bentonite Slurry Quality.

A - 34

GENERAL

Rangsan Silom Precious (present name is Royal Charoen Krung)building is located at the corner of Silom and Charoen Krung Roads, Bang Rak, Bangkok. It is a 63-storey tower with six basement levels constructed by using top-down method. Foundation bored piles of 1.5m in diameter founded in sand layer at depths up to 60m, support the building. The piles were base-grouted. A 1.02m thick cast in-situ diaphragm wall (toe depth 36.0m below ground level) was used for basement excavation and construction. The maximum excavation depth was about 20.0m. 95 built-up steel stanchions pre-founded in bored piles were used for supporting the basement slabs and parts of superstructure during simultaneous construction of basements and the super structure. Three basement slabs, B1, B3 and B5 with openings were used as lateral supports to the diaphragm wall to allow excavation reach to the required depths.

SEAFCO

TYPE OF WORK: Foundation Piles and Diaphragm Walls OWNER: Rangsan Silom Precious Co., Ltd.SUPERSTRUCTURE CONTRACTOR: Samsung (Thailand) Development Co., Ltd.DESIGNER: Siam Engineering Consultants Co., Ltd. PERIOD: 1991-1992

WORK UNDERTAKEN

BORED PILES: Dia. 1.0mx36.0m 5 nos. Dia. 1.5mx60.0m 529 nos. BASE GROUTING: 534 piles STEEL STANCHIONS: Built-up Sections 95 nos. DIAPHRAGM WALLS: 13,748 sq.m. (1.02m Thick) INSTRUMENTATION: 5 Inclinometer Tubes in the wall and 1 Tube in the soil behind the wall.


View of basement construction with top-down method. Diaphragm wall and pile layout.

0 15 25 50m

I-3

I-4

I-5

I-6

I-1 I-2

LEGEND

BORED PILE

DIAPHRAGM WALL PANELINCLINOMETER TUBE

BORED PILE WITH STANCHION

Section of building.

A - 35

Lowering a rebar cage section with box-outs for basement slab connections.

SEAFCO

Excavation below the basement slab.

Floors and basements constructed


All rights reserved. No part of this publication may be reproduced in any form or by any means, without the prior written permission of SEAFCO PUBLIC CO., LTD.

References: Teparaksa, W., Thasnanipan, N. and Tanseng, P. (1999), Analysis of Lateral Wall Movement for Deep Braced Exca-

vation in Bangkok Subsoils, Civil and Environmental Engineering Conference New Frontiers & Challenges, AIT, Bangkok, November 8-12, 1999.

Lee, S. L. and Yong, K. Y. (1992), Base Grouting of Bored Piles, 2nd International Conference on Deep Foundation Practice incorporating PILETALK 1992, Singapore, 4-6 November 1992. Pp. 147-153.

Subsoil conditions.

Undrained Shear Strength

-60

-50

-40

-30

-20

-10

00 10 20 30 40

Su (t/m2)

Dep

th (m

)

BH-1

BH-2

SPT

-60

-50

-40

-30

-20

-10

00 20 40 60 80 100

N (Blows/ft)

Dep

th (m

)

BH-1

BH-2

Top Fill

Soft to Medium Clay

Stiff to Hard Clay

Dense Sand

Hard Silty Clay

Very Dense Sand

Preparation for connections be-tween basement floor and dia-phragm wall.

Diaphragm wall panel excavation.

Installing a 24.0m-long built-up steel stanchion in the borehole.

Pile load test results.

4th FL. +15.303rd FL. +10.80

B1 -2.70B3 -7.90

B5 -13.10B6 -15.70

MAT FOUNDATION

D-WALL-36.0m. -36.0m.

D-WALL

Non-G routed v s. Base-G route d Pile s

0

10

20

30

40

50

60

0 500 1000 1500 2000 2500 3000 3500 4000

Load (ton)

Settl

emen

t (m

m)

N on-Grouted Pile - D ia . 1 .5x60.00mBas e-Grouted Pile A - D ia .1 .5x55.16m (3 Stages - to ta l 2000 ltr)Bas e-Grouted Pile B - D ia .1 .5x60 .00m (3 Stages - to ta l 2000 ltr)

A - 36

GENERAL

The Din Daeng Underpass is the first of its kind in Bangkok Me-tropolis to ease the traffic conges-tion. It is an alternative to flyovers and overpasses. The underpass route extends for 415m with two lanes with one way traffic from the Victory monument. It runs along the middle of the Asoke-Din Daeng Road, and passes under the elevated First Stage Express-way as a cut and cover tunnel. 82m long approach sections at both ends of the underpass were constructed with 0.45m thick rein-forced concrete walls. The 252m long middle section of the under-pass, which includes portals and cut and cover tunnel, is con-structed with 1.0m thick diaphragm walls having toe level 21.0m deep. Cantilever walls and rein-forced concrete strut-supported walls are used in the portal sec-tions. Excavation depths for base slab construction varied from 4.9m to 6.5m below the pavement level.

Layout of Din Daeng Underpass.

TYPE OF WORK: Diaphragm WallOWNER: Bangkok Metropolitan Administration.MAIN CONTRACTOR: Unique Engineering and Construction Co., Ltd. DESIGNER: Epsilon Co., Ltd. PERIOD: 1996 SEAFCO

WORK UNDERTAKEN

DIAPHRAGM WALL: Thickness 1.0m Toe Depth 21.0m 10,545sq.m. INSTRUMENTATION: 8 Inclinometer Tubes in the wall 2 Inclinometer Tubes in the ground behind the wall, 8 Sets of VWSG. and 2 Vibrating Wire Piezometers

Schematic section of cut and cover tunnel.


D02

/99

5 15 35

N

TO ASOKE-DIN DAENG

FROM THE VICTO

RY MONUMENT

DON MUANG

ELEV

ATED

THE

FIRS

TST

AGE

EXPR

ESSW

AY

Diaphragm wall panel excavation in progress.

Drain Pipe

-21.00m

0.00m

Stiff Clay Diaphragm Wall

Soft Clay

Back Fill

-6.50m

A - 37

Diaphragm wall panel excavation with modified grab crane under the existing expressway.

General view of Din Daeng Underpass. Tunnel section.


SEAFCO

References: Thasnanipan, N., Maung, A. W. and Singtogaw, K. (1996). Experience in Construction of an Underpass Tunnel using

Diaphragm Wall Bangkok (in Thai), Technical Seminar on Construction of Basements 1996 organized by Engineering Institute of Thailand, Bangkok, 18 September 1996. Pp. 55-70.

Teparaksa, W., Thasnanipan, N. and Tanseng, P. (1999), Analysis of Lateral Wall Movement for Deep Braced Excava-tion in Bangkok Subsoils, Civil and Environmental Engineering Conference New Frontiers & Challenges, AIT, Bang-kok, November 8-12, 1999.

Subsoil conditions at the Site.

D02

/99

Diaphragm wall panel excavation in the middle of traffics.

Portal section.

S P T

-3 0

-2 5

-2 0

-1 5

-1 0

-5

00 10 20 30 4 0 50 6 0

N (B lo w s /ft)

Dep

th (m

)

B H -1B H -2B H -3B H -4B H -5

U n d ra in e d S h ea r S tre n g th

-30

-25

-20

-15

-10

-5

00 5 10 1 5 20 2 5 30

S u (t/m 2)

Dep

th (m

)

B H -1B H -2B H -3B H -4B H -5

F IL L

S O F T C L A Y

S T IF F C L A Y

M E D IU M D E N S E S A N D

Lowering a rebar cage section.

All rights reserved. No part of this publica-tion may be reproduced in any form or by any means, without the prior written per-mission of SEAFCO PUBLIC CO., LTD.

A - 38

GENERAL

The Thammasat Administration Building project site is located on Tha Prachan Campus, Bangkok nearby the Chao Phraya River. The site is surrounded by a his-torical building and other existing structures. The construction of this building commenced about one year after completion of li-brary building with three base-ments being separated by an ex-isting building. Bored piles with pile tip in dense sand layer are used for supporting the building. A diaphragm wall of 0.8m in thick-ness was designed for excavation 9.7m deep with two levels of tem-porary bracing. The diaphragm wall toe was embedded down to 28.0m to achieve the overall sta-bility of the excavation on the river bank. Various types of instrumen-tation were installed in the wall and existing buildings to observe the ground movements and re-sponse of the buildings during excavation.

Basement section and soil profile.

Excavation and basement construction.

TYPE OF WORK: Foundation Piles, Diaphragm Wall and Excavation OWNER: The Thammasat UniversityMAIN CONTRACTOR: Ch. Karnchang Public Co., Ltd. DESIGNER: SJD-3D Co., Ltd. PERIOD: 1999


SEAFCO

WORK UNDERTAKEN

BORED PILES: Dia. 0.8mx48.0m 17 nos. Dia. 1.0mx48.0m 33 nos. Dia. 1.2mx48.0m 5 nos. Dia. 1.5mx48.0m 23 nos. DIAPHRAGM WALL: 7,742sq.m. (0.8m Thick) EARTH WORK: 59,592cu.m. TEMPORARY BRACING: 586.50 tons INSTRUMENTATION: 6 Inclinometer Tubes, 10 Tiltmeters, 5 Vertical Beam Sensors, VWSGs in one Panel, 4 Earth Pressure Gauges, 20 Surface and Deep Settlement Plates.

+14.80

+11.30

+7.80

+4.30

+0.80

-8.40

-48.00 (Pile Tip)

-28.00 (D-Wall Tip)

0.80m Thick D-Wall Bored Pile

0

10

15

20

25

30

35

Soft toMediumCLAY

Stiff to VeryStiff CLAY

Medium toVery Dense

SAND

0 6 10 20M

+0.70

-3.20-5.80 5

0 20 40 60 80 0 50 100

Vane ShearStrength (kPa)

SPT-N (Blows/ft)

Phase 1Phase 2


A - 39

Excavation completed to the final depth.

Layout of instrumentation and the project site.

SEAFCO

References: Thasnanipan, N., Maung A. W. and Tanseng, P. (1999), Behavior and Performance of Diaphragm Walls under Unbal-

anced Lateral Loading along the Chao Phraya River, 5th International Symposium on Field Measurements in Geome-chanics FMGM99, 1-3 December, 1999, Singapore. Pp 267-272.

Teparaksa, W., Thasnanipan, N. and Tanseng, P. (1999), Analysis of Lateral Wall Movement for Deep Braced Exca-vation in Bangkok Subsoils, Civil and Environmental Engineering Conference New Frontiers & Challenges, AIT, Bangkok, November 8-12, 1999.

Thasnanipan, N., Maung A. W., Tanseng, P. and Wei, S. H. (1998), Performance of a Braced Excavation in Bangkok Clay, Diaphragm Wall Subject to Unbalanced Loading Conditions, 13th Southeast Asian Geotechnical Conference, 16-20 November, 1998, Taipei, Taiwan, ROC. Pp 655-660.

EL4

T4

S5

T5

S6

EL2

D5 S7

T6

D6

EL3

T1

EL1

T2

S1

D1

D9 S9

T9

D7

S8D8

EL5T10

D10 S10

T8

S3D3

D4S4

I-6

S2D2

I-1 I-2

I-3

I-4I-5

5Storey

Building

5 Storey Building 5 Storey Building

5Storey

Building

Chao Phraya River

T3

T7

LegendInclinometer in D-WallTilt plateVertical beam sensorSurface settlement plate (1.0m)

Deep settlement plate (5.0m)0 6 10 20m

Earth pressure gaugePre-load location

EP-1


All rights reserved. No part of this publication may be reproduced in any form or by any means, without the prior written per-m i s s i o n o f SEAFCO PUBLIC CO., LTD.

Bored Pile 0.8x5.98m

0.0

5.0

10.0

15.0

20.0

0 200 400 600 800

Load (Tons)S

ettle

men

t (m

m)

Temporary bracing and working platform.

Pile load test results.

Pre-loading the struts. Earth pressure gauges for checking the strut force. Preparation for base slab casting.

A - 40

GENERAL

The Sathorn Complex project is planned for a multipurpose office and shopping complex. It is lo-cated at the Sathorn and Rama IV Road intersection. The foun-dation bored piles and barrettes are embedded 60m deep in sand layer to support the building. A 0.8m thick cast in-situ diaphragm wall 18.0m in depth, with three- level temporary bracing was ini-tially planned for construction of a four-level basement. After com-pletion of diaphragm construction, basement excavation was later modified with four level-bracing to allow excavation down to 15.5m below ground level for construc-tion of five basement levels. For the foundation in the area of the main tower, barrettes were em-ployed together with bored piles to increase load bearing capacity. Bored piles and barrettes were also incorporated as legs in the diaphragm wall to carry the load of building.

Foundation and diaphragm wall layout.

TYPE OF WORK: Foundation Piles, Diaphragm Wall and BarrettesOWNER: Quality Houses Public Company Limited.MAIN CONTRACTOR: Kay-Thai Co., Ltd. DESIGNER: K.C.S. Associates Co., Ltd. PERIOD: 1995-1996

Pile load test result.

SEAFCO

WORK UNDERTAKEN

BORED PILES: Dia. 1.2mx60.0m 443 nos. BARRETTES: 0.8mX2.7mX60.0m 50 nos. DIAPHRAGM WALL: 7,002sq.m. (0.8m Thick) INSTRUMENTATION: 4 Inclinometer Tubes in the wall

Basement excavation and construction sequence (Schematic).


120.25

89.35

Excavation -15.5m

Excavation -14.0m

Bored PileBarretteInclinometer Tube

I-3

I-2

I-1

I-4

-2.40

-5.10

-9.00

-11.80

-14.00

-18.00

-1.50

- 4.20

-6.90

-9.60

-12.30-13.30

-15.50

LEGEND

2

+1.70

-18.00

1

2

3

4

5

6

9

8

10

11

1213

1

1415

16

CONSTRUCTION STAGE

TEMPORARY BRACING

66

7

BORED PILE 1.2m. TOE DEPTH 60.17m.

-40

-35

-30

-25

-20

-15

-10

-5

00 175 350 525 700 875 1050 1225 1400 1575 1750 1925

LAOD (Tons.)

SETT

LEM

ENT

(mm

.)

A - 41

Lowering a reinforcement cage attached with incli-nometer tube void former.

Work in progress.

Exposed diaphragm wall. Exposed barrette top sections.


SEAFCO

References: Thasnanipan, N. and Singtogaw, K. (1996), Construction of Diaphragm Wall and Bored Piling for Sathorn Complex

Project (in Thai), Technical Seminar and Site Visit on Construction of Deep Basements using Short Embedded Dia-phragm Wall in Bangkok, organized by Engineering Institute of Thailand. Bangkok, 19 December 1996. Pp. 129-143.

Teparaksa, W., Thasnanipan, N., Maung, A. W. and Wei, S. H. (1998), Prediction and Performances of Short Embed-ded Cast In-situ Diaphragm Wall for Deep Excavation in Bangkok Subsoil, Fourth International Conference on Case Histories in Geotechnical Engineering, St. Louis, Missouri, March 9-12, 1998. Pp. 686-692.


Subsoil conditions at the site.

-27.0

-24.0

-21.0

-18.0

-15.0

-12.0

-9.0

-6.0

-3.0

0.00 5 10 15 20 25

Su (t/m2)

Dep

th (m

)

BH-1

BH-2

SPT N

-27.0

-24.0

-21.0

-18.0

-15.0

-12.0

-9.0

-6.0

-3.0

0.00 10 20 30 40

(Blows/ft)

Dep

th (m

)

Top Fill

Soft Clay

Medium to Very Stiff Clay

Dense Sand


A - 42

GENERAL

The Rajavej Hospital is located on Phayathai Road, Rajatheewi, Bangkok. It has five basement levels constructed with top-down method for car parking and rooms for utilities. Foundation bored piles of 0.8m, 1.2m and 1.5m in diameter founded in sand layer at depths of 58m, support the building. A 1.0m thick cast in-situ diaphragm wall (toe depth 21.0m below ground level) was used for basement excavation and construction. The maximum excavation depth was about 14.5m. 80 steel stanchions pre-founded in bored piles were used for supporting the basement slabs and parts of superstructure during simultaneous construction of basements and the super structure. Two basement slabs, B1 and B3 with openings were used as lateral supports for the diaphragm wall to allow excava-tion to the required depths.

SEAFCO

TYPE OF WORK: Foundation Piles and Diaphragm Wall OWNER: Rajavej Hospital Co., Ltd.SUPERSTRUCTURE CONTRACTOR: SAE Thailand Co., Ltd.DESIGNER: P & CYGNA Consultants Co., Ltd. PERIOD: 1994-1995

WORK UNDERTAKEN

BORED PILES: Dia. 1.0mx58.0m 5 nos. Dia. 1.2mx58.0m 114 nos. Dia. 1.5mx58.0m 56 nos. STEEL STANCHIONS: 414x405-498x432mm 80 nos. DIAPHRAGM WALL: 6,058 sq.m. (1.0m Thick) INSTRUMENTATION: 7 Inclinometer Tubes in the wall.

Basement section. Lowering a steel stanchion into borehole before casting the pile.


Diaphragm wall and foundation layout.

0 6 10 20m

I-1

I-2

I-3

I-4

I-5

I-7

I-6

BORED PILE 1.20m.BORED PILE 0.80m.

BORED PILE 1.50m.STEEL STANCHIONINCLINOMETER TUBE

INDEX

B3

B1

-6.7m

0.0m

-11.8m

-14.5m

D-WALL

BOREDPILE

-21.0m

A - 43

21m-long reinforcement cage with box-outs for basement slab connections.

SEAFCO

Basement slab with temporary open-ings for excavation work.

Excavation below the basement slab.



0 6 10 20m

OPENING

OPE

NIN

G

B3 SLAB

References: Thasnanipan, N. and Singtogaw, K. (1996), Bored Piling and Diaphragm Wall Work for Excavation of Five-level Base-

ment of Rajavej Hospital (in Thai), Technical Seminar and Site Visit on Experience in Construction of Deep Base-ments in Bangkok Soft Clay, organized by Engineering Institute of Thailand. Bangkok, 26 March 1996. Pp. 104-140.


Subsoil conditions.

Undrained Shear Strength

-60

-50

-40

-30

-20

-10

00 10 20 30 40

Su (t/m2)

Dep

th (m

)

BH-1

BH-2

SPT

-60

-50

-40

-30

-20

-10

00 20 40 60 80 100

N (Blows/ft)

Dep

th (m

)

BH-1

BH-2

Top Fill

Soft to Medium Clay

Stiff to Hard Clay

Dense Sand

Hard Silty Clay

Very Dense Sand

0

10

20

30

40

50

0 500 1000 1500 2000

BORED PILE DIA. 1.2mX58.16mApplied Load (Tons)

Pile

Hea

d M

ovem

ent (

mm

)

Excavation at final depth of 14.5m below ground level.


Installing a 18.0m-long steel stanchion in the borehole.

Pile load test result.

A - 44

KABAR AYE EXECUTIVE RESIDENCE Bored Piling & Diaphragm Wall Works

- - - - -

j

T

T

1

PROCEEDINGS OF THE THIRTEENTH SOUTHEAST ASIAN GEOTECHNICAL CONFERENCE November 16-20 1998, Taipei, ROC Barrettes Founded in Bangkok Subsoils, Construction and Performance N. Thasnanipan, A. W. Maung and P. Tanseng Seafco Co., Ltd., Bangkok, Thailand

Sponsored by; Chinese Institute of Civil and Hydraulic Engineering Southeast Asian Geotechnical Society

3

Thirteenth Southeast Asian Geotechnical Conference, 16-20 November, 1998, Taipei, Taiwan, ROC

Barrettes Founded in Bangkok Subsoils, Construction and Performance

N. THASNANIPAN SEAFCO Co., Ltd., Bangkok, Thailand

A. W. MAUNG SEAFCO Co., Ltd., Bangkok, Thailand

P. TANSENG SEAFCO Co., Ltd., Bangkok, Thailand

SYNOPSIS Barrettes become not an uncommon foundation element used to support multi-storey buildings, elevated expressways and underground station boxes in Bangkok, Thailand. The demand for barrettes is necessitated mainly by constraints of site conditions, construction method, equipment and extensive bearing capacity requirement, etc. This paper presents construction practice and the performance of barrette constructed in Bangkok metropolis. Trial trenching near a canal for assessment of trench stability and soil deformation are presented. Choice of barrette and common defects found in barrette are also discussed. INTRODUCTION Recently published papers indicate that barrettes become a common foundation type used in various soil conditions to carry very high load for sky scrapers. Development of properties and infrastructures such as construction of multi-storied buildings, elevated expressways, subway railway stations, etc. demand deep foundations with large bearing capacity in Bangkok metropolis, Thailand. Bangkok is well known for its subsoils constraints especially, by the presence of thick soft clay on the top, followed by a series of alternating stiff clay or hard clay and dense or medium dense sand layers. Due to not only the subsoil conditions, but also non-availability of adequate construction area and overlapping developments above and underground, barrettes become common to replace the usual large diameter bored cast in-situ piles in circular shape. The earliest barrettes of 0.82mx2.98m-3.0m with toe depth of 50m were constructed in Bangkok around 1985 for International Trade Centre building in conjunction with diaphragm wall for basement construction. The first static load test on a barrette (0.82x2.7x61.8m) in Bangkok was carried out in 1992 for a 55 storey building on Silom Road, Bangkok. CONSTRUCTION METHOD Normally a cable hung grab mounted on crawler crane is used for trenching under supporting fluid which is commonly bentonite slurry. Concrete pouring is carried out under bentonite slurry using tremie pipes. Properties of

slurry used for trenching in Bangkok subsoil usually comply with DFCP-4 of the Oil Companies Materials Association and the Institution of Civil Engineers (ICE) Specification for Piling and Embedded Retaining Walls. The usual bentonite slurry properties specified are 1.10g/ml for density, 30-50sec for viscosity (Marsh cone), 8-11.5 for pH and not more than 4% for sand content. Usually 3m to 6m long sections of steel tremie pipe of 25cm in diameter are joined together to form a continuous pipe with required length for concrete pouring under the slurry. Cast-in-situ reinforced concrete, pre-cast concrete and temporary steel box guide walls appropriate for site conditions are used for trenching. In normal site conditions, guide walls with a minimum depth of 1.2m are commonly used. Base grouting is also used to improve the capacity and performance of barrettes if necessary. Generally an average rate of excavation about 10-15m2/hr is achieved with mechanical grab in Bangkok subsoil. Usually, excavation rate decreases with increment in excavation depth, having non-linear relationship between excavation time and depth. Figure 1 illustrates excavation time and rate vs. excavation depth for barrettes of 1.50x3.00x55.00m. with no site constraint and idling time.

573

4

0.00

4.00

8.00

12.00

16.00

20.00

24.00

0.00 10.00 20.00 30.00 40.00 50.00 60.00Depth (m)

Tim

e (H

ours

)

B15B20B3B10B19Best Fit

0.00

5.00

10.00

15.00

20.00

25.00

30.00

0.00 10.00 20.00 30.00 40.00 50.00 60.00Depth (m)

Exc

avat

ion

Rat

e (m

2/hr

)

B15B20B3B10B19Best Fit

Soft clay Stiff clay Med. sand V. stiff clay Dense sand

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

1

Figure 1. Excavation time, rate vs. depth for barrettes 1.5mx3.0m. Usually 1.0m or more over casting of concrete above designed cutoff level is practiced. Observation of 3 completed projects indicates that concrete over break of barrettes was found to be in a range of 6% to 14% for barrettes with about 2.0m over casting. TRENCH STABILITY In general site conditions, Bangkok soft clay layer with undrained shear strength value of 15- 20 kPa does not pose a particular problem for trench stability during barrette excavation under bentonite slurry. However trenching in the close vicinity of the river or canal/khlong required careful assessment of soil properties, especially sensitivity and natural water content of the soft clay and presence of permeable soil layers connecting the river bed with high pore pressure. Normally, higher guide wall with adequate slurry pressure and reinforcement of the surrounding soft clay by sheet piles placed perpendicular to the alignment of the planned barrette and driven to a stiffer soil layer, overcome the instability of the trench.

TRIAL TRENCH PERFORMANCE A trial trench (0.8mx2.7mx14m), with above mentioned soil reinforcement close to the canal and high slurry head, was carried out to study the feasibility in construction of barrettes to support the elevated expressway across the Canal. The major concern was stability of 11.0m thick soft clay layer (Fig. 2) which has a very low shear strength less than 15 kPa and natural water content of up to 80%. The planned trench was about 1.5m away from the canal water and four reinforced sheet piles were installed between the trench and the canal prior to excavation. In addition to the reinforced sheet piles, a temporary sheet pile wall was also constructed for protection of slurry spillage into the canal as the local authorities strictly required.

TOP SOIL

SOFTCLAY

MEDIUMCLAY

Slurry Level Guide Wall

Canal

SteelSheet Pile

After 24 Hours

After 48 Hours

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

0 100Creep (mm)

Dep

th (

m)

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

-100 0Creep (mm)

Dep

th (m

)

Figure 2. Soil movements on opposite faces of trial trench The trial trench filled with bentonite slurry was open for 48 hour after excavation down to 14m. Lateral movements of trench face along the depth were studied with graphs of the trench profiles plotted by a Koden drilling monitoring equipment stationed at a fix position on the guide wall at every 6 hour interval. Trench profiles plotted were compared and changes were manually measured using the reference scales shown on the graph. The recording accuracy of the equipment is in a range of +/- 0.2% (in this case the accuracy would be within 2-3mm). 20mm to 30mm lateral soil movement inward the trench was observed on the monitoring records on non-reinforced soil side after 24 hours

574

5

and 48 hours respectively in the soft clay layer. For trench face close to the canal , observed movements of the soil being reinforced with sheet piles are generally less than those of non reinforced soil and some movements are considered induced by the sheet pile wall installed for canal water protection. A profile of trench showing soil movement plotted from the monitoring records is presented in Figure 2. There is no particular problem associated with trench stability in the sand layers 20 to 45m of typical Bangkok subsoil below the ground level. The drilling monitoring records show no collapse of trench surface along the depth section (Fig. 3).

Figure 3. Trench profile of barrette (1.5mx3.0mx55m) plotted by Koden drilling monitoring equipment LOAD BEARING CAPACITY OF BARRETTES Common type of barrettes constructed in Bangkok area is rectangular shape with dimensions ranging from 0.6mx2.7m to 1.0mx2.7m. These barrettes have been mostly constructed incorporated into diaphragm walls for deep basements of high rise buildings. However, individual larger barrettes (1.2mx2.7m and 1.5mx3.0m) are also currently in use to support large column loads as the grabs of large dimensions are currently available in the market. A number of load test on such large barrettes will be carried out in the near future. Maximum bearing capacity of barrettes is usually designed up to allowable concrete stress of 5MPa. Toe depth of barrettes are limited by subsoil conditions and required load

capacity with safety factor of 2.0 to 2.5. The toe depth of constructed barrettes ranges from 45.0m to 60.0m. Concrete cube strength of 30MPa to 40MPa are commonly used for barrettes. Minimum reinforcement of 0.5% of the cross sectional area of barrette is usually provided for either full length or partially as per load requirements. Barrettes can be constructed with flexible layout plan for both vertical and lateral loads. The layout pattern of barrettes can be arranged in a continuous row or column, radial, alternating long and short axis of barrette and a combination of two or more of such patterns. One type of equipment can be used for constructing both barrettes and diaphragm walls in particular projects thus reduces the mobilization cost. In addition to the large bearing capacity requirements, on site difficulties such as limited head room, also demands the barrettes. Piling rigs cannot be utilized under such situations like presence of high voltage power cables overhead, existing overpasses or structures for elevated expressways and planned subway stations. A summary of observation on barrettes of 19 projects completed, with respect to selection criteria is presented in Table 1. Table 1. Summary of Barrette Selection

Criterion No. of

Project

Remarks

High Load Capacity 4 incorporated with bored piles

Minimise Construction Equipment

6 Alternative for bored piles

Limited Head Room for Excavation

2 Elevated Highways under or above existing structures/power lines

Combination with Diaphragm Wall

10 As diaphragm wall legs

Foundation as well as portion of column

3 provision for the future requirement

Since basic shape of the cross section of barrette is rectangular, certain dimensions of barrette can provide a greater perimeter for skin friction than that of the conventional bored pile (in circular shape) with equivalent cross sectional area. Hence, for friction piles, more load carrying capacity per unit volume of concrete can be achieved by a barrette than that of a circular bored pile. Figure 4 illustrates that typical barrette of 2.7m with various thickness can give 12 to 30% higher friction area than that of circular piles with corresponding equivalent sectional area.

575

6

0123456789

1011

0 1 2 3 4 5 6 7 8

Equivalent Gross Cross-sectional Area (m2)

Peri

met

er (m

)

Perimeter ofSquarePerimeter ofCircleBarrette 2.7x X

Figure 4. Comparison of shape effect between barrette and circular pile QUALITY CONTROL Construction tolerance allowed for barrettes are generally identical to that for bored piles. Normally verticality of 1:100 is allowed in barrette construction in Thailand. Drilling monitoring is employed to check the verticality of the trench on random barrettes or on all barrettes. After construction, integrity testing such as sonic integrity (low strain dynamic test) and sonic logging tests and concrete coring are sometimes applied. Common defects found in barrettes constructed in Bangkok subsoils are presented in Table 2. Table 2. Common Defects Found in Barrettes

Defect found Possible Causes

Concrete cover improper cage position, provision of inadequate spacers

Bentonite slurry inclusion or poor quality concrete

improper tremie concrete pouring, improper desanding and recycling of slurry, inadequate concrete slump

Reinforcement cage deviation

inadequate supervision

Uplift of reinforcement cage

improper tremie concrete pouring (with very long tremie pipe embedment in concrete poured) in partially reinforced barrettes

PERFORMANCE OF BARRETTES Available load test results, 4 nos of static load test and one dynamic load test, are summarized below in Table 3. Table 3. Summary of Barrette Load Test Project Barrette

Dimension (m)

Test Load (kN)

Total Settlement (mm)

Permanent Settlement (mm)

A 0.82x2.70x 61.80*

14000 28000 35000

4.83 12.56 17.63

0 0 3.47

B 0.82x2.70x 44.00

12000 24000

5.65 34.15

0.15 24.72

C 0.80x2.70x 55.00

12900 25800 30140

4.46 11.01 12.35

0.24 2.10 2.17

D 0.80x2.70x 50.00

11000 27500

3.07 7.97

0.21 0.15

E 1.00x2.70x 48.94**

20555 14.00 3.0

Note: * with base grouting ** load test by dynamic load All the barrettes tested, except the barrette of project B were founded in dense sand layer with embeddment more than 5m into it. The barrette of project B was embedded into about 0.5m in dense sand layer and failed under the maximum test load of 24MN. Base grouting was employed for the barrette of project A. A soil profile and load vs. settlement graph of test barrette of project A are presented in Figures 5 and 6 respectively.

SOFTCLAY

STIFFCLAY

DENSESAND

DENSESAND

SILTYCLAY

SILTYCLAY

DENSESAND

-7 0

-6 4

-5 8

-5 2

-4 6

-4 0

-3 4

-2 8

-2 2

-1 6

-1 0

-4

0 5 0 1 0 0

SPT-N (BLOWS/30cm)

Figure 5. Soil profile at project A site

576

7

0

5

10

15

20

25

30

35

40

0 10 20 30 40

Load (MN)Se

ttle

men

t (m

m)

Cycle - 1

Cycle - 2

Cycle - 3

Figure 6. Load vs. settlement graph of barrette load test - Project A. Barrettes of project E were constructed on both side of water supply canal and one barrette was tested with high strain dynamic load test as no anchor piles were available. A 200kN steel hammer was dropped at a height of 2.6m above the pile cap. A graph of dynamic load test signal analysis and simulated load settlement curve are shown in Figures 7 and 8 respectively.

Figure 7. High strain dynamic load test signal (force and velocity) and PDA analysis - Project E

Figure 8. Project E -Simulated load settlement curves (PDA) DEPTH

(m)

SOFTCLAY

SILTYCLAY

SILTY SAND

SPT-N (BLOWS/30cm)

FILL

-6 6

-6 3

-6 0

-5 7

-5 4

-5 1

-4 8

-4 5

-4 2

-3 9

-3 6

-3 3

-3 0

-2 7

-2 4

-2 1

-1 8

-1 5

-1 2

-9

-6

-3

00 5 0 1 0 0

Figure 9. A soil profile of Project E site Load test results listed in Table 3 indicate that all barrettes tested are able to carry the design load with Factor of Safety of 2 or higher. From the available load test results, the end bearing capacity of test barrettes cannot be estimated. However, all barrettes are considered as friction piles, except for project A in which base grouting was used to improve the end bearing of barrette. For test barrette of project A, no permanent settlement was observed under test load of 28MN which is 200% of the design load and base grouting is considered contributed in good performance of barrette. Barrette load tests with full instrumentation devices such as strain gauges and magnetic extensometers are planned to be carried out for subway stations in the near futures. The

577

8

performance of barrettes in Bangkok subsoil can then be evaluated with a great accuracy. CONCLUSION Construction practice adopted in the foundation industry for barrette installation in Bangkok subsoil has been discussed in this paper. There is no indication of trench instability under bentonite slurry in Bangkok subsoil for barrette construction with proper site preparation. This is evidenced by trial trenching and profiles plotted by drilling monitoring equipment. To achieve a good end bearing capacity for barrette founded in sand, base grouting is recommended. Performance of barrettes has been discussed with available load test results, and found to be satisfactory with load bearing performance. ACKNOWLEDGEMENT The authors express their appreciation to the colleagues, especially to Mr. Ganeshan Baskaran and Mr. Muhammad Ashfaq Anwar for their invaluable suggestion and assistance in preparation of this paper. REFERENCES Schlosser F., Simon B. and Morey J., (1989) High

Capacity Barrette in a Region of Old Underground Quarries, Proceedings of the International Conference on Piling and Deep Foundations. London, 15-18 May 1989. Pp 119-130.

Woo S. M., Lee K.H. and Hsieh K.J. (1993) The Causes of

Cast-In-Situ Diaphragm Wall Defects, Eleventh Southeast Asian Geotechnical Conference, 4-8 May, 1993, Singapore, Pp 793-798.

Ho C. E. (1993) Deep Barrette Foundation in Sigapore

Weathered Granite Eleventh Southeast Asian Geotechnical Conference, 4-8 May, Singapore, Pp 529-534.

Ho C. E. and Lim C. H. (1998) Barrettes Designed as

Friction Foundations: A Case History, Fourth International Conference on Case Histories in Geotechnical Engineering, St. Louis, Missouri, USA. March 9-12, 236-241.

Dibiagio E and Myrvoll F. (1983) Full Scale Field Test of a Slurry Trench Excavation in Soft Clay, Proceedings of the Conference on Instrumentation in Civil and Geotechnical Engineering, 4-5 July 1983 Singapore. Pp 49-58.

578

Fourth International Conference on

Case Histories in Geotechnical Engineering March 8 12, 1998, St. Louis, Missouri, USA

Editor : Shamsher Prakash Design, construction and behavior of bored cast-in-situ concrete piles in Bangkok subsoils Thasnanipan N. , Maung A. W. and Ganeshan B. SEAFCO Co., Ltd., Bangkok, Thailand Teparaksa W. Chulalongkhon University, Bangkok, Thailand

University of Missouri-Rolla Rolla, Missouri

9

Fourth International Conference on

Case Histories in Geotechnical Engineering March 8 12, 1998, St. Louis, Missouri, USA

Editor : Shamsher Prakash Design, construction and behavior of bored cast-in-situ concrete piles in Bangkok subsoils Thasnanipan N. , Maung A. W. and Ganeshan B. SEAFCO Co., Ltd., Bangkok, Thailand Teparaksa W. Chulalongkhon University, Bangkok, Thailand

University of Missouri-Rolla Rolla, Missouri

11

281

Proceedings: Fourth International Conference on Case Histories in Geotechnical Engineering, St. Louis, Missouri, March 9-12, 1998

DESIGN, CONSTRUCTION AND BEHAVIOUR OF BORED CAST IN-SITU CONCRETE PILES IN BANGKOK SUB SOIL Narong Thasnanipan Wanchai Teparaksa Aung Win Maung Ganeshan Baskaran Paper No.1.20 Seafco Co., Ltd. Civil Engineering Dept. Seafco Co., Ltd. Seafco Co., Ltd. Bangkok 10320 Chulalongkorn University Bangkok 10320 Bangkok 10320 Thailand Bangkok 10330 Thailand Thailand Thailand ABSTRACT This paper briefs design considerations, construction methods and materials, static load test results and pile integrity test results of the cast in-situ bored piles constructed as foundation

Documents

Seafco Research Development