Model test on failure and control mechanism of surrounding rocks in tunnels with super large sections

This paper aims to explore the deformation and failure mechanism of surrounding rock of small spacing tunnel with super large sections. A geo-mechanical model test was carried out with the Ganggou Tunnel in China as engineering background. Tunnel excavation with and without high strength support were simulated in the experimental test. The effect of high strength support on rock displacement, stress evolution, and mechanical characteristics of support components were analyzed. Afterward, an overloading test was conducted for different overburden depths. Conclusions regarding the deformation and failure mechanism of surrounding rock are developed by comparing with and without high strength support.