Physical model experiment research on evolution process of water inrush hazard in a deep-buried tunnel containing the filling fault

In deep tunnel engineering, water inrush disasters caused by filling faults occur frequently, which has generated wide interest in the fields of rock mechanics and fluid mechanics. The rock mass similar material was prepared with river sand as aggregate, cement as a binder, and clay as a regulator, and the similar material of the fault was composed of river sand and gravel, which laid a good foundation for the development of physical model experiment. Then, using the self-designed visualization test system of the two-dimensional model of a deep-buried tunnel filling fault water inrush, four physical models were laid by changing the fault width, fault cross distance, and fault cross angle to study the influence of different hydraulic pressures. In addition, the evolution process of water inrush disaster and the distribution characteristics of seepage weakening failure zone, hydraulic buckling failure zone, and excavation disturbance failure zone were analyzed and discussed. Furthermore, the justification classifications of tunnel risk were established to characterize the process of water-inrush of different schemes for different loading water pressure. The research results further reveal the evolution characteristics of rock fissures, connection, and formation of water inrush channels, and provide an important basis for reducing and controlling the occurrence of such tunnel water inrush disasters.