A pair of Robbins EPBMs have been launched to excavate twin tubes in part of China’s first high speed rail link, which is being constructed between Guangzhou and Foshan.
Excavation with the second of the 6.3m diameter shields is just getting underway just after the launch of the first TBM, in mid-December.
The machines were launched from a 16m deep shaft and the drives will pass through stations of Jushu, Xilang and Hedong, and the bores are to be completed before the end of the year. The TBMs will each drive a total of 2.6km, driving the both tubes in two sections.
Geology along the alignments is comprised of weathered rock, coarse sand, and silt at pressures up to 4 bar. The shields are fitted with disc cutters and rippers to deal with the mixed face conditions.
The running tunnels are being lined with precast concrete rings (5+1) with 300mm thick segments.
Robbins assembled the TBMs and back-up systems in Guangzhou for the twin tubes on Lot 12 of the Guang-Fo line. The high speed link between Guangzhou to Foshan will be 33km long.
The line is part of the Government’s Pearl River Delta Inter-City Rapid Rail Project, which started construction just over 18 months ago and is to completed by 2015. In total, the major project involves placing a total of approximately 32km in tunnel, and constructing 21 stations, 14 of which are to be operational in 2010.
