Study On Movement And Deformation Law Of Overlying Strata Caused By Mining Of Soft Rock Working Face

The protective layer mining and pressure relief gas drainage is the first regional gas control measures.In the process of protective layer mining,the stress-strain state and the gas stress dynamic state of the protected coal seam can be changed to achieve the effect of pressure relief.The elastic potential in the coal seam can be released,the permeability of the coal seam will be improved,the gas flow of the protected coal seam will increase,and the gas will be desorbed in a large amount,thus reducing the coal content and internal energy to prevent the coal and gas purpose.During the advance of the working face,the original stress balance of the surrounding rock is broken,and the overlying strata are out of balance due to the stress and other stress of the rock mass,resulting in movement and deformation.The movement of the rock formations closest to the working face is greatest and the crust of the rock mass is the largest,and the caving zone is formed near the mined-out area.The fissures in the upper rock mass of the caving zone are developed,The fissure area in the body;the upper part of the fissure zone to maintain a good stability,was a regular sinking.Due to the possible existence of groundwater in the overlying strata,the coal seam and other buildings on the surface can accurately determine the movement and possible influence of the strata overlying strata,and the actual production and The development of security measures has a very large guiding significance.In the absence of a suitable coal seam as a protective layer of mining can choose a relatively reasonable rock face as a protective layer for mining.Based on the actual production situation of soft rock working face in Luling Mine,this paper explores the deformation and deformation of overburden caused by mining after soft rock working face by similar simulation experiment,and measures the position of mined-out area under different propulsion distance The stress of the overlying strata in the vertical direction and the displacement caused by the analysis of the data obtained by the analysis and finishing,combined with the experimental results of the overburden movement deformation of the "three belt" range of pre-judgment,explore the soft rock face as the upper The effect of mining layer of protective layer of coal seam.In order to understand the movement and deformation of the overburden,this paper analyzes the factors that may cause the deformation and deformation of the overburden after the mining of the soft rock face with the numerical simulation method.The stress magnitude and displacement of the upper strata in the middle of the mined-out area in the direction of the working face and the direction of the working area are used to determine the range of the "three zones" by the magnitude and nature of the main stress acting on the rock mass The effect of surface as protective layer of upper coal seam.The simulation results obtained by the two experimental methods have a good reference value for the actual production.