Sensitivity Analysis of Soft Rock Mechanics Parameters on Tunnel Mechanics Characteristic

The physical and mechanical parameters of surrounding rock have great influence on the stability of construction. In order to fully grasp the construction mechanical characteristics of surrounding rock highway tunnel under different mechanical parameters in Wudang schist tunnel, the in-situ measurement and numerical calculation are both used for sensitivity analysis of four mechanical parameters to the mechanical characteristics of surrounding rock-lining. The result shows that the sensitivity of E to deformation of surrounding tunnel is greatest, followed by μ, and both sensitivity far outweigh the one of C, φ. Sensitivity of C, φ on stress around the working face are larger than others. And sensitivities of these parameters to lining are different from stress and deformation. The sequences of sensitivity in a decreasing order, are the deformation modulus, the Poissons ratio, cohesion force and friction angle. However four parameters of sensitivity are not significant. These results provide reference on structure design, construction monitoring, disaster control in soft rock tunnel.