Study on the Strain Localization Phenomenon and Mining Overburden Rockmass Fracture
|School||Anhui University of Technology|
|Keywords||Srtain localization Shear band Numerical simulation Overburden|
Strain localization of rock also known as the deformation localization, refers to the material in the process of loading, when reaches a critical level, higher plastic strain in the area of stenosis. The form of destructional forms is rarely performance for the entire system completely destroyed, but damage localization in some areas.In this paper, through theoretical analysis on localization shear zone and rock specimen are analyzed, and on the basis of2141(3) working face of Panyi Coal Mine as the research object for simulation and analysis, obtaining the following conclusions:1. In the theoretical analysis of the localization shear band priming mechanism, the bifurcation point is the localization shear band from the start2. Through the establishment of mechanical model of spring-cement rod-slide a microscopic chain unit, through the mechanics on the chain units within the three occur in the process of mechanical process of macroscopic failure of rock specimens from the microscopic failure series analysis.Research the class Ⅱ deformation satisfies the conditions of rock system through the rock on parts of class Ⅱ behavior conditions.3. Through simulation on flat specimens, the rock sample size effect, the internal defects in materials, friction coefficient and load in the end, both ends of the rock sample loading rate on shear zone formed by the specimen has a certain effect.4. Through the simulation of stope different mining heights analysis found in the mining overburden are appear the phenomenon of shear band, and with the increase of mining step,localization shear zone of overlying strata overlying continued to expand.