Prediction Research On Coal Mine Entry Destabilization Based On Wavelet Analysis

With the coal mining level extending gradurally, instability of roadway surrounding rock induced dynamic disaster occurred frequently. It is important to been given much more concern about the mechanism and rule of instability of roadway surrounding rock.Taken stability control of roadway between extremely steep seams in Wudong colliery into consideration, geological occurrence characteristics of roadway could be analyized and achieved through geology investigation. Based on rock mechanics test to obtain the constitutive relation of coal and rock materials With the help of wavelet analysis program, the acoustic emission signal, unleashed during rock mechanics test, were dealed with to deal with. Inner coeffience between energy, stress and critical energy criterion for instability of surrounding rock of roadway could be determined. We could obtain the critical damage energy judgment of surrounding rock. Researches show that: when energy is bigger than 6.0×104 specimens damage occurred; Acoustic emission monitoring system was here to collect the released dynamic information of the instability of roadway surrounding rock. It was dedicated that the range of dynamic instability of 43# coal seam southern roadway reached to be 1.3m; the range of dynamic instability of 45# coal seam southern roadway was 2.6m. Through optical borehole peeping system, the internal fracture informations of roadways surrounding rock were collected. Combined with loose circle monitor system, the loose range of 43# coal seam and 45# coal seam in southern roadway surrounding rock were determined to be 1.6m and 2.5m respectively. Comprehensive analysis of three kinds monitoring methods, it was dedicated that the dynamic instability of roadway surrounding rock reached 1.6m in +500 level 43# coal seam, the instability of the surrounding rock of 45# coal seam in south range was 2.6m. Finally combined with the actual Wudon geological occurrence characteristics and the above research we could optimize the original supporting method. Much more resonable supporting method and support parameters were selected to ensure the safety of roadway in the exploitation.The research results provide guidance and reference for the safety mining in similar geological conditions.