On 31.08.2015 a 14 m diameter dual-mode EPB TBM was launched in Hong Kong at the north portal of the tunnel that will link the north-eastern New Territories and the Liantang border crossing in mainland China.
Dragages Hong Kong Ltd will be working at the Liantang/ Heung Yuen Wai Boundary Control Point until 2018. This contract is the site formation and infrastructure works - Contract 2 (CV/2012/08), valued at EUR1.19 billion. It includes the construction of a dual two-lane trunk road with about 0.4km of road and 4.8km of tunnel. This will connect the Fanling Interchange with the proposed Sha Tau Kok Interchange.The contractor will install a ventilation system, and provide E&M works and building services for the Lung Shan tunnel and Cheung Shan tunnel and their portal buildings, tunnel administration building adjacent to Wo Keng Shan Road and associated landscaping works, drainage / sewerage, waterworks, utilities and traffic engineering works.
Several seismic fault areas have been identified in the northern section, and Dragages Hong Kong has chosen to use an EPB TBM which is able to adapt to the different geological conditions along the route.The TBM is equipped with two innovative solutions namely Mobydic and Telemach, which enable real-time mapping of rock faces, as well as detection and robotic replacement of damaged components, reducing the need for manual inspection of the cutter head. These technologies, which improve site efficiency, significantly optimize site workers’ safety and working conditions.
To minimize disruption to the community, the operation of the TBM has also been improved and movement from one tunnel to the other will take place inside a 21-m high, 23-m wide cavern, whose excavation has just started.This dual-mode EPB TBM, is also unique in terms of its “3-step” operation. First, the TBM slides into the 200m-long, 23m-wide south bound tunnel; second, the TBM will continue to drive while enlarging the tunnel behind the machine; and third, the TBM will turn from one tunnel to the other inside the mid-vent cavern. This “3-step” operation is a technical first, minimizing disruption to the community while also improving efficiency.To allow for the entry of the TBM, a 200m-long, 23m-wide tunnel has been excavated.
North Portal
At the North Portal excavation commenced in May 2014 and approximately 530,000m3 of materials were excavated and removed from site, forming the tunnel portals and paving the way for the site installations of the TBM. At its peak, 15 excavators (each 80T) and 500 dump trucks were deployed each day.
The 20m-high temporary wall will soon be completed to allow the construction of the North Bound Tunnel. All work is being carried out simultaneously.
South Portal
Upon completion of the temporary steel bridge, constructed over the MTR railway, some 128,100m3 of earthworks conducted in hard rock stratum and substantial completion of site installation works were achieved in the 2nd quarter of 2015. Excavation of the North Bound Tunnel by traditional methods commenced in April 2015. The progress of works has been going smoothly, with 42 m now completed. In the South Bound Tunnel, the project team has managed to reach 23 m Full Face, despite very hard rock conditions. Blasting operations are scheduled to commence in the 4th quarter of 2015. In the course of conducting blasting preparatory works, foundation works and wall construction of the South Ventilation Building are now also in full swing.
Mid-vent
Following completion of the 320m-long entrance by traditional drill & blast they then started the excavation of the 21m-high, 23m-wide and 47m-long cavern that will accept the arrival of the 14m-diameter dual-mode EPB TBM in 2016. Visit http://www.lthywbcp.com.hk/ and http://dragageshk.com/. 41/15.
