PLC Panel on Planning, Lands & Works
Special Meeting on 29 August 1997

Information Paper on SLOPE SAFETY

Introduction

The Government has accorded very high priority and put in very significant efforts and resources in dealing with the issue of slope safety in Hong Kong. Recommendations on slope safety were given in the Morgenstern Report, in the Slope Safety Review Report and in the Select Committee Report on the Kwun Lung Lau Landslide. The report of the Select Committee, published in July 1995, contained a number of detailed recommendations relating to the slope safety programme, many of which endorsed the Morgenstern and Slope Safety Review recommendations and existing practice. Progress on the implementation of the recommendations in these three Reports and other related issues has been reported regularly to the previous LegCo Panel at about 6 months intervals. The last information paper on this issue was submitted in May 97. Subject to this Panel's advice, we will be pleased to continue to keep Members informed of our progress and to seek Members' support on our future efforts and new proposals.

With reference to the letter of 23.8.97 from the Panel, our response to the three points of concern raised by Dr Hon Raymond HO Chung-tai is presented in the following parts of this paper.

Review of Standards

1. Would the Government carry out a comprehensive review of the standards in investigation(, design) and maintenance of slopes?

The Geotechnical Engineering Office (GEO) has the responsibility to set standards for investigation, design, construction and maintenance of slopes. It constantly keeps such standards under review. In setting standards it consults with the profession in Hong Kong and with experts in the field in other countries. It also has the advice of the Slope Safety Technical Review Board which was set up in 1995 for this purpose. The type of failure that occurred recently at Ching Cheung Road of a slope which had been studied under the LPM Programme is very rare and we are very concerned about it. A detailed study has been commenced to ascertain the cause of the landslip. Once the results and conclusions of the investigation are available, careful consideration will be given to any changes to standards that may be necessary in the light of the lessons learnt.

Landslip Preventive Measures (LPM) Programme

2. What is the progress of the 5-year Accelerated LPM Project? Would the government allocate more funding to follow up on the LPM Programme?

A total of about $2.8 billion has been committed for the 5-year Accelerated LPM Project, which commenced in April 1995. The target of this 5-year Project is to upgrade about 850 government slopes and to study about 1450 private slopes. Because the slopes upgraded in the LPM Programme are selected on the basis that they pose the greatest risk to life, it is estimated that, on completion of this Project by 2000, the risk from slope failure arising from the pre-1977 man-made slopes will be reduced by 50% as compared with the risk level in 1977.

So far, 16 consultancy agreements and 12 works contracts have been awarded. 2 more consultancy agreements and 17 works contracts are planned to be awarded in the remainder of this 5-year Project. Currently the Project is on schedule to meet its targets by March 2000.

Following on the completion of the current 5-year Accelerated LPM Project in 2000, we are planning a new LPM programme to deal with the man-made slopes to be registered in the New Catalogue of Slopes. More funding and man-power would definitely have to be allocated to the new LPM Programme, so that more government slopes could be upgraded, and more private slopes could be investigated under the new programme. This will further reduce the landslide risk to a large extent.

It should also be noted that while the LPM Programme is an important part of the Government's slope safety system, the checking of the designs of new slopes and retaining walls by the GEO is also very important and constitutes a major part of the GEO's routine activities. Some 11,500 geotechncial submissions were checked by GEO staff in 1996/97, including those for private developments as well as for public works. This continuing effort, which commenced when the GEO was set up in 1977, provides a mechanism by which the number of substandard slopes would be effectively frozen at the 1977 level.

Legislation to require Professional Slope Inspections

3. As there is no provision in the Buildings Ordinance to compel private slope owners to engage qualified professional Geotechnical Engineers for the inspection of their slopes, would the Government propose legislation on such requirement?

The main problems with the maintenance of private slopes are related to the private owners' low awareness and reluctance towards their maintenance responsibility. Our approach has been to promote their awareness through publicity and education programmes; to provide more information on their slopes and technical assistance; and to strengthen legislative enforcement (e.g. through the Dangerous Hillside Orders under the Buildings Ordinance) as well as to consider a mandatory slope safety inspection scheme, with appropriate sanction for non-compliance. The register of maintenance responsibility being produced by Lands Department under the SIMAR (Systematic Identification of Maintenance Responsibilities of Man-made Slopes) project is an important step to enhance public awareness of slope safety since the public would then know who is responsible for maintaining each slope.

An inter-departmental Standing Committee on Slope Safety has been considering a mandatory Slope Safety Inspection Scheme, which will compel the owners to engage suitably qualified geotechnical engineers to ensure compliance of slope maintenance standards promulgated by GEO in GEOGUIDE 5: Guide to Slope Maintenance. However, prerequisites to the success of such a scheme would be the availability of the SIMAR results and effective legal sanctions for situations with multi-ownerships. Works Bureau will keep the issue under review and devise an effective mandatory slope safety inspection scheme after the SIMAR results are all available.

Works Bureau
August 1997