Research On The Surface Movement Of Coal Pillars In The Strip Of Gangue Filling Mining

Strip mining is an important technical means for coal mining under buildings,water bodies,and railways,but due to its low recovery rate,resulting in a lot of waste of resources.As a green mining method,the gangue filling method can effectively control the surface movement and deformation of the secondary mining,and at the same time solve the problem that the gangue does not go down the well.Taking the strip mining face and the remaining coal pillars in the 12 mining area of a coal mine in Shandong Province as the engineering background,the subject was studied using field measurement,theoretical analysis,numerical simulation,orthogonal test,probability integral prediction and other methods.Based on the measured data of surface movement and deformation of strip mining in the mining area,the general characteristics of the surface movement value of strip mining are analyzed,the general laws of surface movement and deformation in the process of strip mining are summarized,and the predicted parameters of surface probability integrals are reversely analyzed.The numerical simulation method is used to study the movement and deformation of the surface and overburden,the distribution of the plastic zone of the overburden,and the vertical stress distribution of the overburden.The relationship between the maximum subsidence value and the maximum horizontal movement value with the number of strip face mining is analyzed.The basic principle of strip coal pillar filling and mining is expounded,and the mechanical characteristics of the control system of "bearing rock layer+coal pillar+gangue filling body" are analyzed,and its mechanical model is established.The width of secondary mining and the size of coal pillars were theoretically analyzed,and the load calculation was carried out.The formula for calculating the total amount of rock subsidence is derived.Numerical simulation of strip coal pillars with backfill mining was carried out.Carry out the back analysis of the parameters of the probabilistic integral prediction on the measured data,and carry out the probabilistic integral prediction.The results show that the surface villages are within the allowable destruction range,and the coal mining under the mining railway meets the regulations.The relationship between the maximum subsidence value and the maximum horizontal movement value and the decrease of the filling rate is analyzed.Adopt the method of numerical simulation and plan design using orthogonal experiment idea,and conduct sensitivity analysis on the factors affecting the surface movement and deformation of secondary mining width,filling rate and filling body strength.The regression equation is established on the basis of the orthogonal test results,and the regression effect is significant.