ABSTRACT
This chapter presents the results of a review of the sub-surface drainage provisions for recompacted fill slopes in Hong Kong and proposes means to enhance their robustness and effectiveness. Soil fill slopes formed by end-tipping without proper compaction were common in Hong Kong prior to the establishment of the Geotechnical Engineering Office in 1977. A detailed investigation of the distress at the recompacted fill slope behind the Hong Kong Sanatorium and Hospital revealed that the distress might have been caused by adverse transient groundwater conditions. The specific site setting comprises a fill slope formed over a well-defined old drainage line with concentrated subsurface groundwater flow and the compacted fill at the lower half of the slope was probably underlain by a tongue of fairly permeable loose fill. Inclined and sub-horizontal drainage blankets are provided at the base of the recompacted fill cap for each of the batters of the recompacted fill slope.
