Inspection and stabilisation of the Mid-levels cliffs, Hong Kong

Since 1976 the Geotechnical Engineering Office (GEO) of the Hong Kong Government has had a landslip preventive measures (LPM) programme under which man-made features comprising cut slopes, fill slopes and retaining walls are investigated in priority order and upgraded to modern safety standards where necessary. During 1991–1992 the programme included work to improve the stability of selected rock outcrops and very large boulders on a natural cliff face in the Mid-levels area of Hong Kong Island. This unusual site, with a near-vertical often densely vegetated terrain, posed a number of design and contractual challenges which had to be tackled in a limited time frame due to the climatic conditions prevalent in Hong Kong. Detailed aerial and ground inspections were made, and the need for improvement work determined. Contract tendering took place, and a contract to carry out improvement work was let. Work was completed in mid-1992 at a cost of HK$2.5 million.