IOM3(HK) – Technical visit to MTRC Shatin Central Link 1122– Admiralty South Overrun Tunnel (18 Feb 2017)
A technical visit to the construction site - MTR Shatin to Central Link Contract 1122– Admiralty South Overrun Tunnel was successfully held on 18th February 2017, with 21 participants. We were received by the Client (MTR Corporation), and the Contractor (Vinci), with Dr. Lawrence Lee, Miss Donna Wai (MTRC) and Mr. Keith Lee and Mr. Shadow (Vinci) providing a detailed presentation and tour of the project.
The approximate 700m Admiralty South Overrun Tunnel is the southernmost extent of SCL and is located at the south of Hong Kong Park Ventilation Building (HKB). Works of Contract 1122 include the construction of horse-shoe shaped bifurcation, tunnel fan niche structure and single track turnback tunnel by drill and blast method; construction of secondary structures in the overrun tunnels such as plenums, side walls, corridor walkway and all related fitting-out works. The excavation works commenced in September 2015 and are expected to be completed in 2017.
The participants were introduced to the access shaft – Hong Kong Park part of which is a permanent ventilation building. The Contractor relies on an opening of the shaft as access to the underground site. A gantry crane of 40 tons and a big skip are equipped and it handles spoil mucking out during daytime.
The tunnel excavation is within the South Island Line (SIL) Railway Production Zone. And the tunnel has an approximately 40m separation from the existing Hong Kong West Drainage Tunnel. The Contractor managed to blast in day time to match with the mines explosive delivery. The vibration has been strictly controlled, with close coordination with SIL railway protection/operation team and Drainage Service Department, to minimize the potential influence to the railway operation and the existing drainage tunnel.
The group was also given a tour to see the Drill and Blast tunnel excavation face. Dr. Lawrence Lee, Senior Construction Engineer from the MTRC explained how they managed to blast in close proximity of 5-star hotels in an urban area. Electronic detonators were utilized in the beginning of the work where close to existing structures, then changed to non-electric detonators when further from them. The excavated rock is mainly volcanic tuff with very local granite intrusions, generally good with Q value great than 5..
All in all, we were provided with a good learning opportunity on the use of state-of-art technology in drill and blast works.
On behalf of the IOM3 HK Branch, we would like to thank Dr. Lawrence Lee, Miss Donna Wai (MTRC) and Mr. Keith Lee and Mr. Shadow (Vinci) for providing such a fruitful morning.
Group Pictures with Participants
Dr. Lawrence Lee, Miss Donna Wai (MTRC) and Mr. Keith Lee and Mr. Shadow (Vinci) received appreciation certificate and gift from Honorary Secretary, Kelvin Choi and Honorary Treasurer, Tim Leung.