The Mechanism And Application Of Rock Burst Caused By Dynamic And Static Combined Load In Deep 1200m Mining Area Xingcun Coal Mine

Xingcun Coal Mine belongs to the kilometer deep well, the average depth of third mining area West Wing is 1200 m, the deepest working face reaches 1300 m. the increase of mining depth makes stress level increased in deep coal rock mass, The mine pressure appears more intensely and complexly, especially the frequency and intensity of rockburst is increasing. Geostatic stress is very big in deep coal mine, Static load after influence of structure and mining is heavy. then small mine earthquake close or big mine earthquake far away may cause Rock Burst. So Rock Burst in deep mine is mainly caused by static load, dynamic load is a cause of it, so the research of Rock Burst principle is a great meaning to safety mining in deep coal mine.This paper research the static load in deep coal mine by theoretical analysis, field measurement, numerical simulation etc. It also analysis the static and dynamic different of shallow and deep mine, summed up the unique characteristics of deep load, thus designed the corresponding prevention and control methods. To dynamic load, we describe the main differences between Rock Burst and mine earthquake combined with the field practices, and analysis the effect of roof break and fault movement to Rock Burst. Finally combined with burst mechanism and structure characteristics, we analysised the case of burst caused by small dynamic load and big static load, the case of burst caused by big dynamic load that far.Deep mine mining depth caused by the self weight stress is high, resulting in a static load is far greater than the general shallow mine affected by factors such as construction and mining. according to the measurement, the vertical stress is 31.3~31.6MPa, the biggest horizontal stress is 67.9MPa, the ratio of maximum horizontal stress and vertical stress is 2.1, the effect of tectonic stress is heavy. We simulated the stress condition of 3308 working face by FLAC3 D, it shows that there is stress concentration when extending surface and mining across faults, stress concentration is also exists in front of working face, static load there is heavy.Rock Burst and mine earthquake is coexisting relationship, every disaster is related to quake, but not every quake will cause Rock Burst. This paper analysised the disaster caused by roof break and fault movement, it shows that roof first weighting, periodic weighting, square usually cause the stress concentration, at the same time,the movement of roof rock will produce big energy quake, thus may cause Rock Burst. The rock and coal is usually broken around fault, and fault will cause stress concentration, so it’s difficult to protect the tunnel, when mining across fault in 20 m,it will cause big roof sink and roof break, the release of elastic energy is heavy that may lead to disaster. This paper shows that the protect system can hold the energy of 4.5~6.1k J/m2.According to Rock Burst Mechanism Caused by Dynamic and Static Combined Load, we analysis the Rock Burst influence factors of 3308 working face, evaluated the risk of disaster, came up with control measures daily and in key areas. That lead the production of 3308 working face, and good effect has been achieved.