Research of coal pillar inducing rock burst in L-shaped zone of working face and prevention technology

In order to study the coal pillar in L-shaped zone of working face inducing two kinds of typical rock burst in deep mining,the relation between the position of 705 fully mechanized working face and the corresponding 5 times rock burst records is used to study the stress state and mechanical response of coal pillar under certain confining pressure condition,and the relation between coal pillar unstable failure and load is determined.The stress-strain characteristics of coal pillar under dynamic and static combined load are studied by using the strain-softening model of FLAC^3D numerical simulation.The results show that the change of static load has a greater effect than dynamic load on coal pillar unstable failure.The static load plays a role in storing energy,and dynamic load play a role in inducing rock burst.The paper puts forward to use bolt-mesh-cable support and high-pressure water jet unloading combined technology to prevent rock burst in roadways.The numerical simulation results show that stress distribution of surrounding rock meets the model of strong-soft-strong(3S) structure,and the moment distribution is reasonable.The study conclusions provide theoretical foundation and a new guidance for preventing rock burst by synergistic effect technology in roadways.