Stability Analysis Of Surrounding Rock Mass Of Round Tunnel Under The Action Of Seepage

As the mining engineering constantly to the development of deep, groundwater is one of the environmental factors of hosting rock mass, seepage field affect all the time stress field and displacement field located in the surrounding rock around, especially in the "three highs"(high ground stress, high ground temperature, high pressure water) of deep roadway surrounding rock under the action of seepage field of the surrounding stress field and displacement field of the impact will be to the point of cannot be ignored. In this paper, the method of combining theoretical analysis and numerical simulation is used, and analysis of the stability of the surrounding rock under the action of seepage. Based on the assumption that the material property of rock mass was unchangeable in a small region, the rock mass was divided into some plastic rings. By using the unified strength theory and in combining with the rock strain-softening mechanic model, the post-peak strength and deformation evolution law of surrounding rock, the calculation formula for the zonal disintegration of circular surrounding rock masses under the action of the seepage was derived., and the mechanical behaviors of the tunnel’s elastic zone, the plastic-softening zone and ruptured zone under the action of the seepage were analyzed. Through calculation, comparative analysis was made on the influence factors in the range of the plastic zone with and without the action of seepage, and it came a conclusion that the supporting pressure, tunnel radius and mining depth had very remarkable influence on the range of the circular tunnel’s elastic zone under the action of the seepage. The study indicated that the analysis results were much closer to the practice and can embody the damage process of the surrounding rocks, Then it is studied theoretically under the action of seepage, influencing factors such as the permeability coefficient, lateral pressure coefficient, rock resistant coefficient and the different of the ratio of tension and compression modulus and so on, influence on the stability of surrounding rock of roadway. Flac3d numerical simulation software was used, comparative analysis with the consideration of seepage effect and regardless of seepage effect, the circular roadway stress field, displacement field and plastic zone change law is verified, and in the presence of under seepage action, respectively, discussed the different mining depth of roadway surrounding rock stability influence. So it provided a theoretical basis for the optimization of support design and safety evaluation of underground engineering.