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The computerised borehole database for Lantau was completed, and work commenced on the database for the urban areas of Hong Kong and Kowloon. Standards were also being established for the computerisation of ground investigation records by contractors and consultants. Satellite photographs covering the territory were obtained to generate special purpose images, partly for monitoring suspended sediment offshore; while digital terrain models were under development for use in on-going landslide studies.
The Geotechnical Information Unit (GIU) houses the largest collection of geotechnical data in Hong Kong. It served more than 3 100 users during the year.
The Marine Geotechnology Section carried out research and development work for Port and Airport Development Strategy (PADS) projects, notably on foundations for marine structures and reclamations, and the sea-bed pits for the containment of contaminated mud dredged from development areas.
During the year, there were further improvements to ground investigation, geophysical surveys and soil and rock testing services provided for public works projects. An in-house quality assurance system was in the process of being implemented in the Ground Investigation Section of the Materials Division. A requirement has been introduced for ground investigation data to be submitted in a digital format, with the ultimate aim of setting up a territory-wide database.
A number of major ground investigations were undertaken for the Lantau Port and Tseung Kwan O Development Studies, the Strategic Sewage Disposal Scheme, various reclamation projects, new highway tunnels and for environmental studies at landfill sites. Major marine ground investigation and geophysical surveys were also carried out for the Fill Management Studies. Geophysical and hydrographical surveys were executed to study the environmental effects of dredging activities and marine dumping in Hong Kong waters. An increasing number of chemical analyses, including heavy metal testing, were undertaken for studies on contaminated marine mud.
The GEO manages the Public Works Central Laboratory at Kowloon Bay and seven public works regional laboratories in various parts of the territory. Over 300 000 tests on various construction materials were carried out during 1993. The laboratories are accredited under the Hong Kong Laboratory Accreditation Scheme to carry out tests on construction materials, in addition to providing laboratory calibration services. They are currently preparing for accreditation of soils testing.
Fill Management
The territory's fill resources are managed by the Fill Management Committee, whose secretariat is a unit of the Geotechnical Engineering Office (GEO) of the Civil Engineering Department. The committee was set up in 1989 to make decisions on the reservation, allocation and efficient utilisation of fill resources for government and major private projects.
Up to the end of 1993, some 270 million cubic metres of marine fill had been allocated or reserved and of this amount, approximately 120 million cubic metres had been extracted from the seabed for the construction of reclamations. A further 250 million cubic metres of fill from marine sources and a similar quantity from land sources are needed for reclamations over the next 15 years.
A second role of the committee is to plan the marine disposal of dredged mud, including contaminated mud, and to allocate disposal capacity at the gazetted marine spoil grounds.
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