Minimising dredging for seawall construction in Hong Kong

Abstract

This paper describes the alternative design for the construction of the sea defence wall for Peng Chau Town in Hong Kong that allowed the wall to be constructed with the minimum of marine mud dredging. The design and construction of this seawall demonstrates that rockfill seawalls may be built without substantial mud removal and in a reasonable time period, such that the Environmental Protection Department's requirement to minimise the removal of marine mud may be met. The design was instigated to avoid the risks of dredging adjacent to the old town seawall due to concerns of damage to or even collapse of adjacent houses. The design adopted the installation of wick drains and carefully controlled stages of reclamation to maintain stability during construction. The seawall was constructed by China Harbour Engineering Company for the Territory Development Department.