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. 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. 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. 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. 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.
Traditional foundation design practice in Hong Kong relies, in part, on the British Code of Practice for Foundations (BSI, 1954), together with empirical rules formulated some 40 years ago from local experience with foundations in weathered rocks. Foundation design and construction for projects that require the approval of the Building Authority shall comply with the Buildings Ordinance and related regulations. The Code of Practice for Foundations (BD, 2004a) consolidates the practice commonly used in Hong Kong. Designs in accordance with the code are 'deemed-to-satisfy' the Buildings Ordinance and related regulations. Rational design approaches based on accepted engineering principles are recognised practice and are also allowed in the Code of Practice for Foundations.
This publication is intended as a technical reference document that presents modern methods in the design of foundation. Rational design approaches require a greater geotechnical input including properly planned site investigations, field and laboratory testing, together with consideration of the method of construction. The use of rational methods to back-analyse results of loading tests on instrumented foundations or the monitored behaviour of prototype structures has led to a better understanding of foundation behaviour and enables more reliable and economical design to be employed. This should be continued to further enhance the knowledge such that improvements to foundation design can be made in future projects.