Mechanism and Countermeasure of Segmental Lining Damage Induced by Large Water Inflow from Excavation Face in Shield Tunneling

Abstract

This study investigated the influence of large water inflow from the excavation face on segmental lining damage when the earth-pressure balance (EPB) method was used in shield tunneling in a saturated silty sand layer. A refined numerical approach to investigate the damage mechanism and gradual failure mode of segmental lining was established by using the finite-element program Abaqus. The fluid–solid coupling was considered in simulating the tunneling process. The evolutions of permeability and elastic modulus of the grouting material were taken into account. The concrete damaged plasticity (CDP) model was adopted to model the segmental lining damage caused by large water inflow. Parametric studies were carried out to shed light on the mechanism of the structural response. The numerical analysis highlighted the effectiveness of the proposed method to simulate the lining damage. The mechanism of lining damage caused by large water inflow from the excavation face was identified, and it was found that sufficient water flow toward the tunnel compensated for the water loss from the excavation face and reduced the lining damage. It was also found that continuous grouting was an effective countermeasure to alleviate the lining damage.