Project Summary

Route Overview:

• South Line: 2.33 km, ending at the intersection of Gaoqing West Road and Yaolong Road in Pudong District.

• Pudong South Line Tunnel:

  • Length: 481 meters.

  • Complexity: Despite being short, the tunnel involves high technical complexity, with shield tunnelling to be completed using the GPST method for the first time in Shanghai.

• GPST Method (Super-Shallow Cover Shield Tunnelling):

  • Shallow Overburden: The shallowest cover in the Pudong South and North Line tunnel sections is just 1.7 meters.

  • Tunnelling Process: A 11.66-meter diameter shield machine starts at a working shaft 38 meters deep, crossing Qiantan Avenue under super-shallow cover with a maximum slope of 4.99% and a minimum turning radius of R400m in water-rich silty clay.

  • Shield Tunnel Control: High-precision control of the shield machine's tunneling posture, combined with stability measures and excavation techniques, ensures tunnel stability and minimal environmental impact.

Construction Challenges:

• Ground Disturbance: Super-shallow tunnelling can cause significant ground disturbance and rapid surface settlement.

• Traditional Bentonite Slurry: While it has good pumpability, its poor load-bearing and anti-washout capability isn't sufficient to stabilize the soil in such conditions.