Study on coal face spatial structure model and control related dynamic disasters

Based on the attention paid by the society to the safety of coal industry, the research on control of mining accident becomes more and more important, especially recently, the disaster accident occurs frequently, the safety form is more and more severe. Aiming at controlling dynamic disaster accidents in coal mine, a spatial structure model was modeled. The evolution of stress distribution and structure development in the spatial structure model, as well as the movement of overlying strata and the characteristics of strata behaviors during mining were revealed. Based on the spatial structure model and the mining-induced mechanical characteristics, the causing conditions of dynamic disaster accidents in coal mine, such as roof control, roadway roof control, rock burst, roof water inrush and surface subsidence, and related measures were analyzed, and the quantitative control-decision model of related dynamic disaster accidents was established.In the model, the evolution of “broken arch” and “stress arch” and the correlation between mining-induced stress and overlying strata movement were introduced. The height of the water flowing fractured zone is consistent with that of the “fractured arch”, which is the basis of roof water inrush control, and the method of surface subsidence prediction based on the strata stress model of out-arch was established. The support project of “given load” mode for the direct roof and "given deformation" and "limited deformation" mode for the basic roof were proposed. The possible location of rock burst and the measures were put forward. The criterion of water inrush and the calculation method of the reasonable length of working face and the position of presplitting blasting were presented. A mining-induced subsidence model based on the correlation between working face length and overlying strata fracture length was established, and the range of subsidence was calculated by mechanics.The results showed that the correct establishment of control-decision model was the basis of controlling disaster accident in coal mine. The construction of model realized the development on the control of dynamic disaster accidents in coal mine from qualitative to quantitative and provided a guidance for effective forecast and control of dynamic disaster accidents in coal mine.