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The CV Division organised the captioned visit on 24 February 2024 to provide participants with a unique chance to examine this impressive project.
The scope of the project includes the reconstruction of an existing sewage treatment plant, a temporary sewage treatment plant and a new submarine outfall pipe to Sha Tau Kok Hoi. In particular, the utilisation of Horizontal Directional Drilling (HDD) Method in this project demonstrates impressive engineering accomplishments and notable progress in undersea pipe construction.
Participants also gained valuable insights into the HDD Method. In the project, a 1.8-km-long submarine outfall at a depth of -100 mPD will be constructed. As the drilling is conducted from both the land and sea sides, ensuring the accuracy of the connection points at both ends is crucial. To address this, the project team implemented an Artificial Magnetic Field Guiding system, equipped with signal transmission and reception components from both ends. This system automatically corrects the drilling direction in case of any misalignment.
Following the introduction of the HDD Method, a visit was organised to the reconstructed treatment plant to showcase the implementation of the Design for Manufacture and Assembly (DfMA) solution. Given the tight schedule and limited working area, DfMA proved advantageous by minimising subsequent work and significantly reducing the need for falsework and formwork on site.
Reducing on-site construction activities in this way also reduced the required area for material storage. One noteworthy example of DfMA was the semi-precast matrix deck. This precast element, serving as the bottom layer of the concrete slab, incorporates void former, facilitating transportation and lifting with reduced weight.
Through this visit, participants acquired valuable knowledge and developed a deeper appreciation for the remarkable engineering achievements. Specifically, participants learnt more about pipe drilling technology and their profound impact on the infrastructure of Hong Kong.
The CV Division would like to express our gratitude to the project team for their detailed presentation and arrangements for the visit.