GUIDE TO SITE INVESTIGATION

This Geoguide deals with the investigation of sites in Hong Kong for the purposes of assessing their suitability for civil engineering and building works and of acquiring knowledge of site characteristics that affect the design and construction of such works and t h e security of adjacent properties. It is essentially BS 5930 : 1981, Code of Practice for Site Investigations (BSI, 1981a), modified as considered desirable for use in Hong Kong. While the basic structure and philosophy of BSI (1981a) has been maintained in this Geoguide, topics of particular importance in Hong Kong have been supplemented or rewritten in the light of local conditions and experience. Other sections of BSI (1981a) have been repeated herein without significant amendment, and this has been denoted by an 12al1'c script. Less relevant or rarely-used portions of BSI (1981a) have been incorporated only by reference, or have been specifically deleted. In this Geoguide, as in BSI (1981a). the expression "site investigation" has been used in its wider sense. It is often used elsewhere in a narrow sense to describe what has been termed herein "ground investigation". The use of soil and rock as construction materials is treated only briefly: further information on this is given in BSI (1981b). From Part I1 onwards. this Ceoguide is divided as follows .- Part I/. Part /I deals with those matters of a technical, legal or environmental character that should be taken into account in selecting the site for in determining whether a proposed site is suitable) and in preparing the design of the works. Part I/I. Part 111 discusses general aspects and planning of ground in vestl'gahon, including the influence of general condihons and ground condihbns on the selection of methods of in vestigation. Parts IV and V. Parts IV and V discuss methods of ground investigation, sub-divided as follows : Part IV deals with excavation, boring. sampling, probing and tests in boreholes; Part V deals with field tests and laboratory tests on samples. Part V/. Part V/ deals with the preparation of field reports and borebole logs, the interpretation of the data obtahed from the hvescigafhn and the preparahon of the final site investigation report. The last section of BSI (1981a), which deals with the description of soils and rocks, is not covered in this Geoguide. A companion document. Geoguide 3 : Guide to Rock and Soil Descriptions (GCO. 1988), has been devoted entirely to this topic, and the reader should refer to it for guidance on the description and classification of Hong Kong rocks and soils. It may be noted that there are some imbalances in treatment of the various topics, with, in some cases. more comprehensive coverage given to methods t h a t a r e less frequently used. Because it would not be possible to include full coverage of all available site investigation techniques, methods that are well documented elsewhere in the literature receive abbreviated coverage in this Geoguide. This Geoguide represents a standard of good practice and therefore takes the form of recommendations. Compliance with it does not confer immunity from relevant statutory and legal requirements. The recommendations given are intended only as guidance and should not be taken as mandatory. In this respect, it should be realized that improvements to many of the methods will continue to evolve.