Control Of Rock Burst In Coal Roadway Of Fully-mechanized Sublevel Caving Mine

The fully-mechanized sublevel caving mine mainly concentrated in the western region now,and Huating & Binchang mining area appeared impact dynamic disaster strongly. In order to reduce the harm of such mine rock dynamic disaster, this paper, based on laboratory experiments,theoretical analysis, numerical simulation and field practice, analyzes rock burst mechanism in coal roadway under the condition of the hard and thick coal seam, hard roof and high level of stress etc, and the external cause of the static and dynamic loads changes in seam roadway, puts forward the method of risk monitoring and early warning countermeasures and prevention ideas,at last provide theoretical basis and reference for safe mining under similar conditions.From the statistics, under the condition of delamination and fully mechanized caving mining, the impact appears generally in the process of extractive production(86%); The main performance are the drum(accounting for 88%), support failure(accounting for 43%), roof sink(accounting for 40%), Roof leakage accident occurred near the close of the structure; Impact damage is generally concentrated in the length of 90m(accounting for 87%).Through coal specimen uniaxial loading test and numerical simulation method, analysis the characteristic of coal seam under specific loading conditions, found that coal prone to elastic nuclear and explosive under external static load disturbance. The roadway surrounding failure can be divided into three types of horizontal stress leading, vertical stress leading and dynamic stress leading, according to the different degrees of surrounding rock infected by stresses. Put forward discriminant index of floor impact damage.Simulation show that stress concentration is found in the roadway surrounding rock under the condition of 650 m buried depth, and the maximum is 1.5 times of the original rock stress.Plastic failure of the roof and floor is mainly occurred in the coal seam roadway under the high level stress. Under the condition of high static load, static load is the main energy source of coal and rock failure, dynamic load is to trigger the destruction of coal body, and the energy input of thedynamic load also plays an important role under the condition of low static load.The external leading factors of rock burst in the full coal roadway by fully mechanized caving mining are analyzed. That roadway dynamic and static load and rock state changes caused by mining disturbance, airport multi roadway layout, construction area of high level of stress concentration and fault structure and other factors, when reaching the critical condition of coal and rock failure, prone to impulsive dynamical disasters.In the end, puts forward the prevention and control of the impact pressure under the condition of fully mechanized caving mine. Using seismic wave CT and impact deformational energy technology to predict the spatial impact hazard, and using the stress on line and the ground sound index to predict the spatial impact of time domain. Through the optimization of thetunneling, working face mining distance optimization, and coal pillar optimization to reduce the dangerous degree of the impact area. Take roof blasting to reduce the dynamic and static load source, take coal blasting and large diameter pressure relief hole on two sides of roadway to relief and transfer high stress region and slow impact appearance, take bottom pressure relief hole to reduce bottom plate appearence.