Surrounding rock failure characteristics and surface deformation law under mining of retaining coal pillar
Aiming at the problems of stability and the surface deformation control of the surrounding rock under mining of re-maining coal pillar by Whangavelli method in Yushenfu mining area,we propose a narrow strip cementation filling method and a continuous mining machine mining the remaining coal pillar by Whangavelli,and test the physical and mechanical properties of cemented filling materials.The plastic zone,stope stress evolution law and surface deformation law of the sur-rounding rock under different mining sizes of retaining coal pillar are studied by FLAC3D simulation analysis and surface subsidence prediction.The results show that when the mining size of the remaining coal pillar is 14 m,the plastic zone of the stope coal pillar is seriously damaged,and the maximum vertical stress reaches 19.60 MPa.When the mining size of the re-maining coal pillar is 6 m,the development range of the plastic zone of the coal pillar in the stope is decreased,and the stress peak was only 11.6 MPa.The smaller the filling mining area of working face,the larger the filling rate,resulting in the gradual decrease of the surface deformation influential degree and range.When the filling rate is 95％,the maximum subsid-ence value of the surface is only 46 mm.The filling can effectively control the movement of rock formations and realize wa-ter-conserving coal mining under the water source protection zone.
万方数据
维普
