The road route is designed to create a major east-west thoroughfare to relieve the traffic congestion on the Yan’an Road Elevated Highway, the northern part of Shanghai’s Inner Ring Road as well as other busy north-south routes. The new road, which will take traffic on a six-lane underground expressway with designed driving speeds of 60 km/hour, is due to be completed by the end of 2019.
As part of the construction works, and utilising what is to date the largest diameter tunnelling shield yet used in Shanghai, some 8 km of the route will be in tunnel. Ground conditions along the tunnel route include a 5.5 km section of sandy soil, which it is expected will create some challenges when stabilising the tunnel structure as well as keeping the tunnel on alignment. The work is being undertaken using a Mixshield TBM which will excavate a tunnel of 15.56 m diameter. Due to the required route of the new road the alignment and the need to avoid interference with existing structures, including the flood protection wall along the Suzhou Creek, the tunnel route will include several curves with radii as tight as 500 m. The tunnel route also crosses close to the Shanghai Metro Line 11 and Metro Line 7, which will keep on running during the construction operation.
The ground conditions, allied with the curve requirements of the tunnel, mean that navigation of the tunnel will in itself be a challenge. To ensure that the necessary alignment is met with the required accuracy, the contractor Shanghai Tunnel Engineering Co (STEC) has awarded the navigation equipment contract and support of the navigation process to VMT.
Having previous experience of VMT’s navigation system on previous projects the STEC engineers have spoken highly VMT’s support and the operation of its systems.
For its part, VMT will provide to the tunnelling operation a TUnIS Navigation TBM Laser navigation system, TUnIS Navigation Office software, TUnIS Ring Sequencing monitoring equipment and SLuM Ultra to determine the diameter of every installed ring.
VMT’s TUnIS software was not just developed for navigation and ring sequencing, but also to support the contractor in challenging situations by providing a full overview of recorded data. Where time matters most, the reports and charts created are designed for quick analyses.
All VMT navigation systems come with a personnel setup and training programme carried out by a VMT engineer on site. Thereafter, the jobsite staff, machine operators, tunnel engineers and especially the survey engineers are able to use and control the navigation system themselves.
By the end of 2017 it is planned that the tunnel excavation operation should reach the reception shaft of the route at Zhongshan Park.