Research On Multi-parameter Monitoring Of Deep Compound Dynamic Disaster Risk In Pingdingshan Mining Area

The combined dynamic disaster of rock burst and coal and gas outburst is a complex dynamic phenomenon which is combined by rock burst and coal and gas outburst in deep mining process.Compared with single rock burst or coal and gas outburst,the occurrence mechanism of composite dynamic disasters is more complex,and it is more difficult to predict and prevent them,which brings more technical problems to the safe mining of coal mines.Therefore,according to the characteristics of the complex dynamic disaster in Pingdingshan mining area,the occurrence mechanism and mutual disturbance mechanism of the complex dynamic disaster are studied,and the types of the complex dynamic disaster are divided.On this basis,a multi-parameter drilling monitoring method of the complex dynamic disaster is proposed,and the theoretical and experimental study of the method is carried out.This paper adopts the method of data analysis,theoretical research and field test.In this paper,a multi-parameter drilling monitoring method for rock burst and coal and gas outburst is proposed,which combines the parameters of drill pipe thrust,drill pipe torque,gas desorption value of coal drilling cuttings and drilling cuttings quantity.The principle of monitoring compound dynamic disaster of drill pipe thrust index and drill pipe torque index is analyzed,and the expressions of drill pipe thrust and drill pipe torque are derived.The relationship between gas analytical values of coal drill cuttings and the relationship between k₁.Δh₂ values and gas pressure were verified by laboratory experiments of gas desorption values of coal drill cuttings.Based on the research,the multi-parameter monitoring equipment for composite dynamic disaster drilling was independently developed,and the multi-parameter monitoring technology for composite dynamic disaster was applied in the roadway and working face respectively.Through drilling pipe thrust,drilling pipe torque,gas desorption value of coal drilling cuttings and drilling cuttings quantity index,the distribution of coal pressure relief zone,stress concentration zone and in-situ rock stress zone and gas pressure value in front of working face are judged.By analyzing the test data,it is determined that the pressure relief zone is within the range of 0～5m in the coal and rock mass in front of the test working face,and the width of the pressure relief zone is about 5m.The range of 5～6m is the stress concentration area;After 7m,the stress zone of primary rock is.The downhole observation data show that there is a good consistency between the predicted results of drill pipe thrust,drill pipe torque and cuttings quantity.The critical index of drill pipe thrust is 12kN and the critical index of drill pipe torque is 40N·m by regression analysis,which can be used as a reference index for monitoring complex dynamic disasters in deep mines.The multi-parameter monitoring method of composite dynamic disaster is applied to carry out empirical study in the field.The monitoring data show that when the peak point of each parameter,i.e.the stress concentration area,approaches the coal wall gradually and the gas pressure increases slightly,rock burst disaster or composite dynamic disaster of impact type is easy to occur.When the gas pressure increases step by step and the stress concentration area approaches to the coal wall in a small amplitude,the coal and gas outburst or outburst complex dynamic disaster is easy to occur.Through the field verification,the drilling multi-parameter monitoring method can realize the effective determination of the internal stress distribution state of the coal rock,and evaluate the risk of compound power disaster.There are 38 figures,12 tables and 93 references in this paper.