Technical visit to Shatin Central Link (SCL) Contract 1109 – Stations and Tunnels of Kowloon City Section
IOM3 organized a technical visit to the construction site of Shatin Central Link Contract 1109 - Stations and Tunnels of Kowloon City Section on 11 April 2015. A total of 13 members joined the visit and they spent a fruitful morning with the representatives of the Contractor, Samsung - Hsin Chong Joint Venture.
We were received by Project Director, Mr. Francis Choi, and Project HSEQ Manager, Mr. Jack Lai, who gave a brief introduction on the project, including method of construction as well as current status of works.
Contract 1109 comprises the construction of two stations, Sung Wong Toi station (by cut and cover) and To Kwa Wan station (by top-down method), as well as 1,600 metres of running tunnels to be constructed by Tunnel Boring Machine, and is located in a dense urban area.
The project demonstrated a state-of-art approach to achieve a balance between railway development, and protecting the surrounding environment. Archaeological surveys had indicated the presence of historical artefacts in the To Kwa Wan area, and excavation for the To Kwa Wan Station had unearthed additional archaeological features, which lead to some design amendment.
The participants were briefed on how diaphragm walls had been constructed in very close proximity to old residential buildings, and how protective measures were implemented to secure public safety. Even though construction records of many of the buildings were missing, foundation details were unknown, and buildings were in poor condition, the work was completed safely. Over 1700 monitoring points had been installed in the project.
Afterwards, the group was given a tour of the Tunnel Boring Machine (TBM) Launching Shaft. The participants were able to observe assembly of the slurry TBM and gain an understanding of the launching arrangement, as well as the excavation support system for the launch shaft. To ensure safe launch of the TBM, a combination of ground treatment in front of the breakout point together with pressurized steel cylinder inside the launch shaft had been devised. The site team explained in detail how the universal ring system of precast segmental tunnel lining works, and how the TBM was steered along the required alignment. The use of decompression tables for working in compressed air conditions was explained. Of note was a locomotive training facility set up specifically to allow training of tunnel workers before work commenced.
We would like to express our deepest gratitude to Mr. Francis Choi, Mr. Jack Lai and their team as well as the participants’ support. Our Council Chairman, Mr. Guy Bridges presented souvenirs to express our thanks, and wish the project continued success for the forthcoming TBM excavation work.
Author: Kelvin Choi, Hong Kong Branch, 11 April 2015