Model Test Of Water Inrush Due To Mine Rock Breaking And Numerical Simulation Study

Mine water inrush occurs frequently in China owing to complex and diverse hydrogeological conditions of coal mines, which not only destroyes equipment and adversely affects the duration but also causes heavy casualties and major economic losses. The rescue is difficult, long and costly. Consequently, water inrush will bring about negative social impact. And it has been restricting the development of China's coal production as one of the important factors. In this paper, by physical model test of water inrush due to mine rock breaking, variation of multi-field information before water inrush, such as seepage pressure, displacement, stress, temperature, acoustic emission and resistivity, has been studied in depth. Also the measurable parameters of precursory information which are effective to predict water inrush have been determined. The simulation of water inrush due to mine rock breaking has been carried out to analyze the mechanism of water inrush caused by roof breaking under the influence of the mining seam excavation. A series of meaningful research results have been obtained.Of the multi-field information such as seepage pressure, displacement, stress, temperature, acoustic emission and resistivity, the effective precursory information and its variation has been determined by the model test of water inrush due to mine rock breaking. Based on the similarity theory of three-dimensional fluid-solid coupling, a new type of non-hydrophilic similar material of fluid-solid coupling has been developed; In order to avoid the impact of the traditional steel frame model on resistivity monitoring, extensible test bench has been made by high-strength PVC material; On the basis of FBG technology, fiber grating sensors with small size, good waterproof performance, and strong anti-interference ability have been desigened to the realize the real-ti me parallel acquisition of seepage pressure, displacement, stress, and temperature; The 3-D model test system of fluid-solid coupling has been adopted to do the model test of water-inrush in roadway and mines. The variation of multi-field information before water inrush, such as seepage pressure, displacement, stress, temperature, acoustic emission and resistivity, has been researched. Catastrophic evolution mechanism of water inrush resulted from mine rock breaking under mining excavation has been interpreted. And the sudden changes of precursory information of water inrush have been revealed.Water inrush due to roof separation and collapse in the coal mine water inrush model test has been modeled by FLAC. Interfaces in FLAC are used to simulate bedding planes and fluid-solid coupling calculation has been carried out. The whole process after progressive mining, including roof subsidence, bed separation, the sudden collapse and water inrush, has been be captured. The stress distribution and migration law of flow field have been studied. The numerical results and experimental results agree very well.