The Stability Analyses Of The Laneway Roof In Soft And Hard Interbedded Rocks

The problem of underground project wall rock stablity is a very complex mechanics, Its failure is often as a result of many complex factor working each other. The wall rock distortion and failure we observe is the phenomena of multi-factor working. In coal strata, there are lots of sedimentary rocks, especially soft and hard rocks alternate each other. Many scholars study sedimentary rocks because their intensity and distortion characters are obviously anisotropy.In this paper, Firstly, describe engineering geological properties of layer rocks, emphasizing on analyzing weak intercalation, mud intercalation, cranny between layers, cutting layer cranny, distortion and mechanics properties. Afterwards, looking upon layered rocks as traverse isotropy, on the basis of fast Lagrangian analysis of continua in 3 dimensions, 3D explicit finite difference program is adopted to simulate the failure, defection and subsidence and stress change characters of the structure lay developing and soft and rigid rock alternating each other. Major studying fruits as follows:(1) Putting forward the classifying gist of layered rock masses and dividing into five kinds on the base of thestructure of coal strata and the influence to the stability of wall rock.(2)Studying the variety laws of the plastic failure, distortion and stress of soft and hard rocks alternate-layered roof with the constant vertical stress only the horizontal stress changing.(3)Studying the variety laws of the plastic failure, distortion and stress of soft and hard alternate-layered roof on the condition of different layer thick.(4)Studying the variety laws of the plastic failure, distortion and stress of soft and hard alternate-layered roof on the condition of differ- rent laneway width, when laneway height is constant.The study provide the theory direction to stability, bolt mode and bolt parameter choice of laneway wall rock in soft and hard rocks alternate-layered rockmass. At the same time, let us more deeply know the mechanics actions of the rocks, so that further develop our country underground engineering.