Geotextile Containment Disposal of Type 3 Contaminated Sediments in the Environmental Remediation of Kai Tak Approach Channel,Hong Kong

摘要

Over the years sewage was discharged into the Kai Tak Approach Channel. The channel flows into the Kwun Tong Typhoon Shelter before discharging into Victoria Harbour. Two overlapping breakwaters provide a gap for navigation into the typhoon shelter. The combination of the elongated shape of the water body and the presence of the breakwaters resulted in poor circulation and lead to the accumulation of contaminated sediments on the seabed. The environmental remediation works involved insitu bioremediation treatment of sediments to abate odour impact, dredging of the seabed to ensure sufficient water depth is available to effect odour suppression and improvement in water circulation. The geotextile containment technique was used for the disposal of 120,000 m~3 of Type 3 contaminated sediments at dedicated contaminated mud pits. About 800 geotextile containment units were consumed from December 2011 to August 2012 for the disposal. One geotextile containment unit was instrumented with strain gauges to measure the mobilisation of tension during the disposal process.