Study On The Localization Deformation Of Rock And Roadway Surrounding Rock Failure Mechanism

The localized deformation of the rock is that a large number of shear strain concentration to the oblique section of rock material in the loading process of rock-like materials, Final results of rock localized deformation is the formation of localized shear band. So, Research on the mechanism of rock deformation localization is very necessary in engineering application. In this paper, the starting, development and final formation of the deformation localization shear band for rock-like materials were comprehensive studied by the two methods of theoretical analysis and numerical simulation. In addition, rupture mechanism of roadway surrounding rock was discussed briefly. The main work and achievements are as follows:1.First, reviewing the domestic and foreign research status on localization shear band by three test research of theoretical analysis, numerical simulation and experimental study, Secondly, strain localization deformation of rock materials was analyzed theoretically, The bifurcation condition is caused by the material should be necessary for localization to occur are obtained.2.The start the Mohr-Coulomb theory of rock strain localization based on the mechanics analysis, Derived from the localization shear band critical hardening modulus expression of shear band and expression of azimuth angle under non-associated flow plane and the associated flow plane in two cases.3.To simulate the rock specimens under conditions of plane strain localization shear band formation process by FLAC numerical simulation software, the end face of the effects of the geometry, the unit mesh density and material defects will impact on the formation of shear bands.4. To simulate the ax symmetric compression condition on shear band formation process of the cylinder rock specimens by FLAC numerical simulation software, face effect altitude effect and confining pressure effects will impact on the formation of shear bands.5.Through the establishment of roof beam and the simple mechanics analysis model to obtain the stability condition of tunnel roof rock shear failure, The deformation of roadway surrounding rock were studied by numerical simulation, The surrounding rock of roadway in high stress under the action of shear strain is an important cause of roadway surrounding rock rupture.