Load-Bearing Behavior of Tunnels Reinforced with Shotcrete and Rock Bolts Using Small-Scale Model Testing and the Finite Element Method

Abstract

This study aims to investigate the load-bearing behavior of tunnels through small-scale model testing combined with numerical analysis using the Finite Element Method (FEM). Various tunnel cross-sectional geometries were examined, with particular focus on the horseshoe-shaped tunnel. The study considers the influence of modifying the slenderness ratio of the tunnel opening and the application of reinforcement techniques using shotcrete and rock bolts. Laboratory testing results revealed that horseshoe-shaped tunnels with optimally proportioned opening heights can efficiently withstand compressive loads while providing structural safety and adequate usable space. Concurrently, numerical analyses using FEM exhibited results consistent with experimental observations, particularly in terms of stress distribution (Shading Stress) and maximum total displacement of the tunnel structure. The findings demonstrate that the integration of small-scale physical testing and FEM analysis provides a reliable approach for evaluating tunnel stability and offers practical insights for the structural design of reinforced tunnels.