Study On The Deformation And Movement Of Overlying Strata In The Filling Mining Working Face Of Huo Zhuang Pillar In Yangquhe Mine

The Filling mining working face of Huo Zhuang pillar in Yangquhe mine have achieved disposing of coal gangue and fly ash in underground, the coal extraction ration under the building have been more than 85%. The service life of the mine have been prolonged, the ecological environment and living environment in the mining area have been improved. In this paper, combined with the engineering geological background of the filling working face, the performance of the filling materials are analyzed by the methods of theoretical analysis and physical experiment. Using the numerical simulation software Udec to study the movement and deformation of the overlying strata and the law of crack development under different filling ratio, following conclusions can be drawn:(1)The composition of the filling material and the specific ratio were determined, coal gangue and fly ash filling materials and cement ratio of 8:4:1, special cement content ranged from 70~100kg/ m3. Some material properties of the filling materials were determined, the filling materials of the slump is 20 cm, the stratification degree was 14 mm, the Filling paste oozing rate was 1.63%. The compressive strength of the paste specimen is 4.74~6.2MPa, the peak value of the paste test piece is between 1.0~1.8kN.(2)The Udec numerical simulation software was used to simulate the coal pillar mining, and the movement law of the overlying strata under different filling ratio was obtained. When the filling ratio is 95%, the lead bearing stress is 6MPa, and the maximum settlement is 352 mm, the fracture development is not very obvious, the fracture height is 18 m, the plastic zone is fully developed in the immediate roof, the basic roof is only bent down; when the filling ratio is 85%, the lead bearing stress is 8MPa, and the maximum settlement is 590 mm, the overall development of the crack is extended to the rear of the working face 20~90m, the fracture height is 36m; when the filling ratio is 75%, the lead bearing stress is 14 MPa, and the maximum settlement is 810 mm. the overall development of the crack is extended to the rear of the working face 6~102m, the fracture height is 48 m.(3)The monitoring of roadway surface displacement and surface subsidence is carried out. The actual monitoring results show that the maximum subsidence value of the line is 124 mm, the ground subsidence value is 139 mm, and the remaining surface deformation indicators are in a reasonable range, the control of surface subsidence is controlled by the filling mining.