Pipe jacking or microtunnelling involves the boring of a tunnel for the proposed sewer/drain, by a tunnelling shield (usually by a fully automatic mechanized tunnelling machine or manual excavation inside a hand shield) from a launch shaft towards a reception shaft. The shield is jacked forward incrementally by hydraulic jacks at the launch shaft. As the shield advances, jacking pipes are inserted behind the shield one by one and the whole string is jacked forward. When the tunnelling shield reaches the reception shaft, it is removed and the pipeline is complete. Usually, the tunnelling operation is carried out outside the view and the awareness of the public. Nevertheless, the launch shafts and the reception shafts still need to be excavated, and may need to be in operation throughout the tunnelling operation.
Layout of a Pipejacking / Microtunnelling site |
Drainage Improvement Works in Ki Lun Tsuen, Kwu Tung, Ma Tso Lung and Sha Ling (Nov 2008 to end 2011)
This project involved laying of three numbers of 1,350mm-1,650mm diameter drain pipes of total 40m long across the Fan Kam Road at Ying Pun using pipe jacking method for minimizing the disturbance to the existing Dongjiang watermains and the traffic flow of Fan Kam Road.
Overhead lifting gantry above the jacking pit |
Pipe-jacking in progress inside the jacking pit |
Kai Tak Nullah Improvement Works at Prince Edward Road East (Aug 2010 to end 2013)
This project involved construction of a 1,200mm diameter 35m long precast concrete sewer across Prince Edward Road East using Hand Shield Pipe Jacking Method.
Pipe-jacking in progress inside the jacking pit |
Manual excavation inside the hand shield head for pipe jacking works |
Rehabilitation and construction of trunk sewers underneath Shatin River Channel (Feb 2011 to end 2017)
This project involves construction of about 250 m of a twin pipe trunk sewer underneath Shing Mun River Channel with a diameter of 1,500 mm for each pipe and subsequent rehabilitation of about 250 m of an existing gravity trunk sewer underneath Shing Mun River Channel with a diameter of 2,050 mm.
Setting up of tunnel boring machine in progress |
Sewer laying by pipe jacking method |