Water inrush hazard is one of the major threats in mining tunnel construction. Rock particle migration in the seepage process is the main cause of water inrush pathway and rock instability. In this paper, a radial water–rock mixture flow model is established to study the evolution laws of water inrush and rock instability. The reliability of the proposed model is verified by the experimental data from a previous study. Through the mixture flow model, temporal-spatial evolution laws of different hydraulic and mechanical properties are analysed. And the proposed model’s applicability and limitations are discussed by comparing it with the existing water inrush model. The result shows that this model has high accuracy both in temporal evolution and spatial distribution. The accuracy of the model is related to the fluctuation caused by particle migration and the deviation of the set value. During the seepage, the porosity, permeability, volume discharge rate and volume concentration of the fluidized particle increase rapidly due to the particle migration, and this phenomenon is significant near the fluid outlet. As the seepage progresses, the volume concentration at the outlet decreases rapidly after reaching the peak, which leads to a decrease in the growth rate of permeability and porosity, and finally a stable seepage state can be maintained. In addition, the pore pressure is not fixed during radial particle migration and decreases with particle migration. Under the effect of particle migration, the downward radial displacement and decrease in effective radial stress are observed. In addition, both cohesion and shear stress of the rock material decreased, and the rock instability eventually occurred at the outlet.

突水灾害是矿山巷道施工的主要威胁之一。渗流过程中岩石颗粒的运移是突水路径和岩石失稳的主要原因。本文建立径向水岩混合流模型，研究突水和岩石失稳演化规律。先前研究的实验数据验证了所提出模型的可靠性。通过混合物流模型，分析不同水力和力学特性的时空演化规律。并通过与现有突水模型的比较，讨论了该模型的适用性和局限性。结果表明，该模型在时间演化和空间分布方面均具有较高的准确性。模型的精度与粒子迁移引起的波动和设定值的偏差有关。渗流过程中，由于颗粒的迁移，流化颗粒的孔隙度、渗透率、体积排出速率和体积浓度迅速增加，这种现象在流体出口附近最为显着。随着渗流的进行，出口处的体积浓度达到峰值后迅速降低，导致渗透率和孔隙度的增长速度减小，最终能够维持稳定的渗流状态。此外，孔隙压力在颗粒径向运移过程中并不是固定的，并且随着颗粒运移而减小。在颗粒迁移的作用下，观察到向下的径向位移和有效径向应力的减小。此外，岩石材料的粘聚力和剪应力均下降，最终在出口处发生岩石失稳。