Research On Deformation Rules And Supporting Technology Of Surrounding Rock For Mining Face In Shallow Coal Seam

Development of deformation rules and supporting of surrounding rock for mining face in shallow coal seam has important engineering application value in Shennan mining area 4-2 coal.By the experimental research,theoretical analysis,numerical simulation and field practice combined the methods of work.The main conclusion include:(1)The stress distribution characteristics of the surrounding rock in the shallow coal seam are analyzed.The main factors affecting the deformation of the surrounding rock include the buried depth,the surrounding rock properties,the surrounding rock stress,the mining activity,the support design and the construction quality.There are three kinds of deformation and failure modes of rock mass,including tensile fracture,shear failure and composite failure.(2)The physical and mechanical tests of 4-2 coal samples wepe carried rout,and the parameters such as uniaxial compressive strength,elastic modulus,poisson’s ratio,shear strength and tensile strength were obtained.The In order to understand the whole damage process of coal samples in detail,the triaxial compression test under the approximate confining pressure is carried out.The whole process can be divided into:compaction stage,elastic stage,plastic stage,brittle drop and plastic flow.The two tests provide the basic data for support design research and numerical simulation.(3)According to the geological conditions of the channel surrounding rock,the deformation of the groove and the distribution of the loose ring,the relevant supporting parameters are obtained by theoretical calculation.The stability of the channel surrounding rock and the support effect of the support scheme are evaluated by FLAC numerical simulation method.The simulation results show that the design parameters of the surrounding rock support of the shallow buried channel are reasonable.(4)The law of deformation monitoring of surrounding rock in,mining process of crossheading,get trough surface convergence,surrounding rock displacement,stress,roof subsidence,roof separation,loose circle distribution and advanced hydraulic prop force data.The engineering practice shows that the support scheme is safe and feasible.The research results can provide reference for the other coal mines and other 4-2 coal reserves in the coal mine.