Shanghai Jing’an Temple Pipe-Jacking Project

8.7m x 9.9m STEC EPB Pipe-Jacker

Project Year: 2019

Project Summary:

  • Location: Beneath Huashan Road at the intersection with Yan'an Middle Road.

  • Station Type: Three-level island platform station.

  • Dimensions:

    • Length: 230 meters

    • Width: 20.54 meters

    • Maximum Depth: 26.2 meters

  • Structure:

    • Area A: 105 meters (cut-and-cover method)

    • Area B: 82 meters (pipe jacking method, includes platform and station hall tunnels)

    • Area C: 42 meters (cut-and-cover method)

  • Pipe-Jacker Dimensions:

    • Platform-level tunnel: 8.7m x 9.9m

    • Station hall-level tunnel: 4.88m x 9.5m

Construction Challenges:

  1. Large-section pipe-jacking with small spacing (6 launch and receivings)

  2. Deep cover and complex soil layers (15m deep cover at platform level)

  3. Multiple crossings under municipal pipelines

  4. Close proximity to pedestrian overpasses, elevated bridge piers (minimum distance 3.6m), and 1800 year-old wooden temple

  5. Small spacing for large-section side pipe jacking (only 2m between east and west platform tunnels)

  6. Difficult assembly and flipping of steel pipe segments (9.9m x 8.7m)

Jello-Mud Results:

  • Injection Rate & Soil Conditions:

    • In Shanghai's soft, cohesive soil (water-rich silty clay), the annular injection rate per ring is about 100%, with no soil displacement at the entry point.

  • Ground Settlement & Friction Control:

    • Ground settlement is controlled within ±10mm as per design.

    • Friction coefficient is maintained between 3-4 kN/m².

    • Pipe-jacker torque was reduced to less than 50% of designed torque.

  • Settlement Observations:

    • The maximum settlement of the Yanan Elevated Bridge is only 3.4mm.

    • The maximum settlement of the pedestrian overpass is 3.7mm.

    • Both settlements meet design requirements.

  • Tunnel Alignment & Leakage Control:

    • Tunnel axis control is within ±20mm, meeting metro construction standards.

    • No significant water leakage observed at the launch and receiving shafts or pipe joints, with minimal disturbance.

  • Use of Jello-Mud:

Pipe-jacker exiting the portal with no Jello-Mud or soil on the body, exhibiting good lubrication effect.