China's Largest Robbins Crossover TBM Launches on Pearl River Delta Intercity Railway

摘要

The largest ever Robbins Crossover (XRE) TBM in China launched in late March 2021 in Guangzhou for contractors Sichuan Jinshi Heavy Equipment Leasing Co., Ltd and CREC Bureau 2. The 9.16 m diameter hybrid machine is boring the 2.5 km long Pazhou Line Lot PZH-1 of the Pearl River Delta Intercity Railway Project, which will offer better commutes for Guangzhou residents traveling to and from University City. The machine will encounter various ground types during its bore, from moderately to strongly weathered argillaceous shales and sandstone to mixed face conditions. Much of the rock is fractured, while the quartz content is as high as 50 percent. "Not only are there poor ground conditions such as soft to hard uneven, fractured zones and full-face hard rock, but these sections appear to alternate frequently, which is the biggest challenge of the project," said Yongsheng Qi, Project Manager for Robbins China. The tunnel will also cross under rivers and other bodies of water with a cover of 20 to 31 m. The ground strata connects to the river and is highly permeable, resulting in expected water pressures above 7 bar. The Crossover TBM features both hard rock and EPB modes and is optimized for the rapidly changing ground found on the project. An adaptable cutterhead design and Robbins' Torque-Shift system enable efficient tunneling in hard, mixed, and soft ground.An adaptable screw conveyor can be mounted in the center or bottom of the mixing chamber depending on the mode. The machine is fitted with high pressure seals and can statically hold up to 30 bar water pressure.