Research On Formation Law And Control Of Rock Burst In Fold Structural Area Of Cuimu Coal Mine

Due to the increasing demand for coal in modern society,China’s coal mining centers are expanding towards the northwest.However,the intensification of mining activities and the increasing burial depth of coal seams have resulted in increasingly complex geological conditions in coal mines,and a series of safety issues have arisen due to the challenging mining conditions.In recent years,one of the five mines at the Cuimu Coal Mine owned by Yonglong Company in Shaanxi Province has been deeply affected by rock burst and has experienced frequent incidents of rock burst manifestation.The complex geological conditions and the presence of folded and faulted structures in the mine have provided conditions for the occurrence of rock bursts.Due to the impact of mining activities,a large number of strong mining tremors will be generated in the folded structure areas with high stress concentration,thereby increasing the potential risk of rock burst occurrence.This article focuses on the breeding law of rock bursts in the folded parts during the mining process of the22311 working face of the Cuimu Coal Mine.The article uses modeling tools such as FLAC^3Dand Rhino,and combines theoretical analysis with simulation results.Based on field practice experience,the main controlling factors and breeding laws of rock bursts in the folded structure areas of the Cuimu Coal Mine are studied in depth.The rock burst manifestation characteristics of typical working faces with rock bursts in recent years at the Cuimu Coal Mine were statistically analyzed.Taking the 22311 working face as an example,this thesis analyzes the main influencing factors that may induce the occurrence of rock bursts from the geological conditions and mining conditions.And based on the Analytic Hierarchy Process（AHP）,a systematic safety analysis method is applied to the22311 working face.By analyzing the relative importance of different disaster-causing factors and quantifying the weight of each factor based on past experience,it is possible to more accurately determine the main controlling factors of rock bursts in the 22311 working face.To analyze in depth the disturbance intensity of the coal-rock mass caused by mining-induced stress and its characteristics in changing the original rock stress,a numerical simulation study is carried out based on the drill core column chart and coal seam occurrence in the 22-level area of the Cuimu coal mine.A Rhino surface model is established and imported into FLAC^3D.The correct translation would be:The 22311 working face was divided into five stages,and the influence of the working face mining on the horizontal and vertical stress of the folding structure zone was analyzed based on the three-directional mining stress instability judgment indicators.The danger factors corresponding to different regions were obtained based on the curve of advanced support pressure changes.Based on the microseismic activity characteristics of the 22311 working face in Cuimu Coal Mine,the spatiotemporal evolution rules of microseismic activity at different energy levels during the mining process were summarized,and the relationship between microseismic activity and the mining speed of the working face was obtained.Based on the weighted quantification of five stages,statistical analysis was conducted on the spatiotemporal distribution characteristics of microseismicity and the distribution of microseismic activity in each stage of the 22311 working face.Among them,the microseismic impact characteristics in the fold structure area were analyzed from three aspects:advancing speed,mining area,and influence range.In the area where 22311 working face advances towards X2 and Huayuan inclined seams,the energy and frequency of microseismic events increase.The mining area in the fold zone has a greater impact on microseismic activity,and compared to other mining stages,there is a significant increase in the total energy of microseismic events.In the area where 22311 working face advances towards X2 and Huayuan inclined seams,the energy and frequency of microseismic events increase.The mining area in the fold zone has a greater impact on microseismic activity,and compared to other mining stages,there is a significant increase in the total energy of microseismic events.Through microseismic indicators,cuttings indicators,and CT inversion,it has been proven that after implementing pressure relief measures,the degree of stress concentration in the fold structure zone has decreased,which can provide a reference for safe mining and prevention of rock bursts in working faces under similar geological conditions in the future.There are 98 figures,18 tables and 89 references in this thesis.