Abstract: Aiming at the disaster of rock burst in graben structural area of coal mine, based on the particularity of graben structure and the occurrence characteristics of overburden rock, the movement characteristics of overburden and stress evolution law of coal and rock mass in the graben structural region are analyzed and the corresponding mechanical model is established by means of field investigation, theoretical analysis and numerical simulation. The mechanism of rock burst in the graben structural region is consequently studied. At the same time, the evolution characteristics of microseismic energy and frequency before and after rock burst are analyzed, and the time sequence of microseismic precursory information of rock burst in graben structural region is obtained. The results show that: the sliding subsidence of wedge is closely related to the width of goaf. The existence of goaf in graben structural area will break the stable state of wedge and lead to more severe stability conditions. The local slip and dislocation of FD6 and FD8 faults lead to wedge sliding subsidence, and the hanging roof structure of graben structural area also has corresponding extrusion effect on the undeveloped coal mass. The same action provides high static stress conditions for the occurrence of rock burst, and the breaking of suspended roof structure provides dynamic load disturbance conditions for the occurrence of rock burst. The joint action of static load and dynamic load results in the upper drift and triple entry in the graben structure. The energy and frequency of microseismic show obvious deviation before the impact, and the daily average energy of microseismic is measured. There are obvious sudden drop and sudden rise. The anti-scour technology of “chain-brokening and consumption-increasing” is proposed based on the analysis results and field practice. It provides some theoretical reference value for occurrence mechanism, early warning and prevention and control of rock burst on working face in graben structural area.

Key words: graben structure, rock burst, mechanical model, microseismic, chain-brokening and consumption-increasing