Study on the Coupling Effect Between Surrounding Rock and Support Structures of Tunnels

A coupling analysis system was built considering the interaction between surrounding rock and tunnel support structures. Three indexes including the utilization coefficient of overall performance of the supporting systemη, coupling efficiency of support structures W, and deformation characteristics of tunnel support structures B, were taken into account in this research. The corresponding weight values was obtained using Analytic Hierarchy Process (AHP). In addition, the quantitative analysis method was used to evaluate the influence of degree of coupling between surrounding rock and support structures with the aim of effectively controlling the movement of surrounding rock. The 3D software ANSYS was used to analyze the Yang Ling tunnel in Wu Xi province, China as an example of the coupling analysis system. As the grade level of surrounding rock in Yang Ling tunnel increases from type III to type V, it can be seen that under the condition of type IV the coupling efficiency of surrounding rock and supporting structure was the highest. The obtained results indicated that the method is appropriate for design optimization of tunnel support and studying the interaction between surrounding rock and support structures.