Evolution of delayed water inrush in fault fracture zone considering time effect

The flow properties of a water inrush from a fault fracture zone are important for mining engineering applications. Numerous fault-delayed water inrush cases were analyzed, and it was concluded that the delayed groundwater bursting evolution in the fault fractured zone can be divided into two phases: (i) the activation of faults and (ii) the fault-weakening seepage. Three flow equations that indicate the flow variability of three flow stages in the second phase were established. A finite-element numerical model was established, and the evolution rules of the groundwater flow pattern under the time effect were obtained. Finally, the water inflow over time was calculated. The results were consistent with in situ measurements of the water inflow, which verifies the rationality of the theory.