FOUNDATION DESIGN AND CONSTRUCTION - …

1 GEO PUBLICATION No. 1/2006 FOUNDATION DESIGN AND CONSTRUCTION GEOTECHNICAL ENGINEERING OFFICE Civil Engineering and Development Department The Government of the Hong Kong Special Administrative Region 2 The Government of the Hong Kong Special Administrative Region First published, 2006 Prepared by : Geotechnical Engineering Office, Civil Engineering and Development Department, Civil Engineering and Development Building, 101 Princess Margaret Road, Homantin, Kowloon, Hong Kong. Captions of Figures on the Front Cover Top Left : CONSTRUCTION of Large-diameter Bored Piles Top Right : pile Loading Test Using Osterberg Load Cell Bottom Left : Foundations in Marble Bottom Right : CONSTRUCTION of Large-diameter Bored Piles on Slope 3 FOREWORD This publication is a reference document that presents a review of the principles and practice related to DESIGN and CONSTRUCTION of FOUNDATION , with specific reference to ground conditions in Hong Kong.

2 The information given in the publication should facilitate the use of modern methods and knowledge in FOUNDATION engineering. The Geotechnical Engineering Office published in 1996 a reference document (GEO Publication No. 1/96) on pile DESIGN and CONSTRUCTION with a Hong Kong perspective. In recent years, there has been a growing emphasis on the use of rational DESIGN methods in FOUNDATION engineering. Many high-quality instrumented pile loading tests were conducted, which had resulted in better understanding of pile behaviour and more economic FOUNDATION solutions.

3 The Geotechnical Engineering Office sees the need to revise the publication to consolidate the experience gained and improvement made in the practice of FOUNDATION DESIGN and CONSTRUCTION . The scope of the publication is also expanded to cover the key DESIGN aspects for shallow foundations, in response to the request of the practitioners. Hence, a new publication title is used. The preparation of this publication is under the overall direction of a Working Group. The membership of the Working Group, given on the next page, includes representatives from relevant government departments, the Hong Kong Institution of Engineers and the Hong Kong CONSTRUCTION Association.

4 Copies of a draft version of this document were circulated to local professional bodies, consulting engineers, contractors, academics, government departments and renowned overseas experts in the field of FOUNDATION engineering. Many individuals and organisations made very useful comments, many of which have been adopted in finalising this document. Their contributions are gratefully acknowledged. The data available to us from instrumented pile loading tests in Hong Kong are collated in this publication.

5 Practitioners are encouraged to help expand this pile database by continuing to provide us with raw data from local instrumented pile loading tests. The data can be sent to Chief Geotechnical Engineer/Standards and Testing. Practitioners are encouraged to provide comments to the Geotechnical Engineering Office at any time on the contents of the publication, so that improvements can be made in future editions. Raymond K S Chan Head, Geotechnical Engineering Office January 2006 4 WORKING GROUP : Architectural Services Department Mr.

6 Li Buildings Department Mr. Cheng Civil Engineering and Development Department Mr. Pun (Chairman) Mr. Ken Ho Dr. Richard Pang Mr. Vincent Tse Dr. Dominic Lo Mr. Sammy Cheung (Secretary) Highways Department Mr. Li W. (before 1 December 2004) Mr. Yeung (between 1 December 2004 and 3 May 2005) Mr. Anthony Yuen (after 3 May 2005) Hong Kong CONSTRUCTION Association (Piling Contractor Subcommittee) Mr. David Chiu Hong Kong Institution of Engineers (Civil Division) Mr. Timothy Suen Hong Kong Institution of Engineers (Geotechnical Division) Dr. Daman Lee Hong Kong Institution of Engineers (Structural Division) Mr.

7 Kwan Housing Department Dr. John Lai Mr. Pang 5 CONTENTS Page No. TITLE PAGE 1 FOREWORD 3 WORKING GROUP 4 CONTENTS 5 LIST OF TABLES 15 LIST OF FIGURES 17 LIST OF PLATES 21 1. INTRODUCTION 23 PURPOSE AND SCOPE 23 GENERAL GUIDANCE 24 2.

8 SITE INVESTIGATION, GEOLOGICAL MODELS AND 25 SELECTION OF DESIGN PARAMETERS GENERAL 25 DESK STUDIES 25 Site History 25 Details of Adjacent Structures and Existing Foundations 26 Geological Studies 26 Groundwater 33 EXECUTION OF GROUND

9 INVESTIGATION 33 EXTENT OF GROUND INVESTIGATION 33 General Sites 33 6 Page No. Sites Underlain by Marble 34 SOIL AND ROCK SAMPLING 36 DETECTION OF AGGRESSIVE GROUND 36 INSITU AND LABORATORY TESTING 37 ESTABLISHING A GEOLOGICAL MODEL 38

10 SELECTION OF DESIGN PARAMETERS 39 3. SHALLOW FOUNDATIONS 41 GENERAL 41 DESIGN OF SHALLOW FOUNDATIONS ON SOILS 42 Determination of Bearing Capacity of Soils 42 General 42 Empirical methods 42 Bearing capacity theory 42 Foundations On or Near the Crest of a Slope 46 Factors of Safety 46 Settlement Estimation 48 General 48 Foundations on granular soils 49 Foundations on fine-grained soils 50 Lateral Resistance of Shallow Foundations 51