The surrounding rock deformation and failure mechanism of wudang group schists tunnel

The surrounding rock deformation and failure has been the hot issue of tunnel study. So making clear the rock deformation mechanism is the key to solve this kind of problem. The article analysised the deformation and failure mode of the tunnel rock, explored the deformation mechanism of the surrounding rock, based on the research of the engineering geological conditions and the deformation characteristics of surrounding rock of the Tongsheng tunnel. The results showed that: (1)There were two modes of the surrounding rock deformation and failure - The symmetric mode and the asymmetric mode. Under the symmetric mode, rock stress, displacement and plastic zone were in the level symmetric distribution form; while under the asymmetric mode, the hoop stress values of the cave would increase approximately 15%, the distribution of the rock stress, displacement, plastic zone would deflect. After the deflecting, the ellipse's long axis of the hoop stress always in the quadrant of the original symmetric mode, and was intersected with foliation of moderate angle (40 ° ~ 55 °). (2)The surrounding rock deformation and failure mechanisms were summarized as follows: Different foliation loft lead to different magnitude and distribution of the hoop stress around the holes, however the distribution of the hoop stress around the holes presented certain cross-cut relationship with the foliation loft, formed two kinds of deformation and failure modes. The results can provide a reference for the design, construction of schist area under construction or proposed project. © 2015 ejge.