Research on nonlinear mechanics design method of bolt-net-anchor coupling support for deep soft rock tunnel

For the engineering rock mass media of soft rock tunnel has been in the plastic and large deformation stage and its deformation and fail are caused by the un-coupling between support and surrounding rock, a nonlinear mechanics design method of bolt-net-anchor coupling support is put forward; and it includes deformation design, strength design and feedback design. This design method is different from the classic design method, it is the parameters design. The coupling support parameters of bolt-net-anchor got by strength design are based on the optimum coupling procedure got by deformation design, and can be modified by feed back design in the supporting period of tunnel. Different from the new Austrian tunneling method, using this design method can realized the coupling on the strength, rigidity and structure between support and surrounding rock by bolt-net support interior surrounding rock and anchor to mobilize the intension of exterior rock.