LAND, PUBLIC WORKS AND UTILITIES
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provide useful advice to private slope owners to help them maintain and improve their slopes.
During the year, the GEO completed a study on the use of geophysical investigation techniques to assist in the identification of weak soils that may adversely affect slope stability. Two geophysical methods were found to be useful and were introduced for use in selected landslide and slope studies. A magnetic survey was completed for Hong Kong waters, and this provided improved regional perspective on faults and other geological structures. Two new geological memoirs, presenting a comprehensive review of the geology of Hong Kong, were published.
The Geotechnical Information Unit in the Civil Engineering Library houses the largest collection of geotechnical data in Hong Kong. It is open to the public, and served more than 36 000 users during 2000.
The GEO provides material testing and ground investigation services to support land production and infrastructure projects. The Public Works Laboratories (PWL) operated by the office (consisting of the Public Works Central Laboratory at Kowloon Bay and six Public Works Regional Laboratories in various parts of Hong Kong), carry out specific tests on construction materials and provide calibration tests. In 2000, some 410 000 tests were carried out through the PWL and in the GEO's ground investigation term contracts, and the length of soil and rock drilled totalled 9 600 metres.
In 2000, the GEO continued to provide specialist geotechnical advisory services to government departments. The intent of the services is to help government departments achieve a high standard of geotechnical works and to assist them to find. cost-effective solutions. These services include the provision of ad-hoc geotechnical advice and carrying out feasibility studies, detailed investigations, design and construction supervision for a wide range of public works projects, such as road improvement works at Ap Lei Chau North Coastal Road and Clearwater Bay Road; road widening and footbridge improvement works at Ap Lei Chau Bridge Road; road widening works and mitigation of natural terrain landslides at Tsing Yi North Coastal Road, Yam O Tuk Service Reservoirs and the Teleport project at Chung Hom Kok; boulder and slope stabilisation works at Tseung Kwan O Area 137 and Yung Shue Wan; reclamation works at North Tsing Yi; regulation works (Stage III) at Shenzhen River; and flood protection works at East San Tin and other regions in the north-western New Territories.
The Slope Maintenance Audit Section of the GEO continued to assist maintenance departments to improve their performance in discharging their slope maintenance. responsibilities. First-round audits of government slope maintenance works had been completed, and identified improvements had been substantially implemented by the maintenance departments. The second-round audits will begin in early 2001.
Fill Supply and Mud Disposal
The Fill Management Committee (FMC) was established in 1989 as an intra- governmental committee to manage the use of fill resources and disposal of dredged mud in Hong Kong. In order to streamline the administrative process and to strengthen management of construction and demolition materials, the FMC was reorganised in April into the Marine Fill Committee (MFC) and Public Fill Committee (PFC). The MFC is responsible for identifying and managing the supply