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Structural Stability Monitoring of Model Test on Highway Tunnel with Lining Backside Voids Using Dynamic and Static
Chaofei Du1, Chuanbo Zhou1, Nan Jiang1
1Faculty of Engineering, China University of Geosciences, Wuhan 430074, China.
Sensors (Basel, Switzerland)
|February 11, 2023
Summary
Voids behind tunnel linings significantly increase stress, particularly at the vault. Deeper voids pose a greater risk to tunnel structural stability than longer ones, requiring careful maintenance.
Area of Science:
- Geotechnical Engineering
- Civil Engineering
- Structural Analysis
Background:
- Voids behind tunnel linings can arise from construction defects or erosion.
- These voids compromise the rock-lining interaction and can lead to structural instability.
- Understanding void impact is crucial for safe tunnel operation.
Purpose of the Study:
- To investigate the influence of voids behind tunnel linings on structural stability.
- To analyze stress variations in tunnel linings due to voids of varying size and position.
Main Methods:
- A laboratory model of a tunnel lining was constructed, simulating voids behind the lining.
- The position and size of voids were systematically altered to observe stress changes.
- Stress distribution and variations in the lining were measured and analyzed.
Main Results:
- Voids behind the lining increase stress concentrations, especially near the vault.
- Both circumferential and axial stresses rise with void depth and length.
- Void depth has a more significant impact on lining stress than void length.
- A 30 mm void depth at the vault caused a 178.2% increase in axial tensile stress.
Conclusions:
- Voids behind tunnel linings critically affect structural stability.
- Void depth is a primary factor influencing lining stress.
- Prioritize addressing voids, particularly deep ones, during tunnel maintenance.
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