Tunnel Face Test System

System Description

The Tunnel Face Model Testing System is designed for research on the stability of shield tunnel excavation faces. The model box has dimensions of **1.5 m (L) × 1.0 m (W) × 1.5 m (H)**. It enables dynamic simulation of tunnel excavation in laboratory tests to investigate excavation face instability. The system can measure surface displacement, pore water pressure, soil deformation, and other parameters of the tunnel face under various soil layer combinations and confined water conditions, supporting studies on the interactions between tunnel, soil and groundwater. During testing, image acquisition equipment is used to dynamically capture data including surface settlement, pore water pressure, internal force distribution in the model box, and soil movement images of symmetric sections. Using the retraction rate and displacement of the moving panel as control parameters, the system investigates the excavation face support pressure and ground deformation laws under different working conditions. Particle Image Velocimetry (PIV) technology is applied to analyze the displacement increment field and shear strain increment field of the excavation face instability zone at different support plate retraction rates.