Flow Catastrophe Evolution Laws of Nonlinear Seepage for Water Inrush Induced by Conductive Fault

Abstract

Geological defects, such as conductive faults, karst conduits, fracture zones and so on, often lead to serious water inrush disaster, because they frequently become potential water inrush passage especially when large water bearing structure exists. This will cause high construction risks of water inrush. Water inrush process is the catastrophe evolution process of flow state for conductive fault. The initial stage of the catastrophe evolution process is the water seepage in confined aquifer, which then develops into rapid flow in the fault. The last stage manifests as conduit flow in the tunnel. Brinkman equation has been adopted for the seepage characteristic description of karst water in fault. Based on the conservation of mass and pressure balance, Darcy equation and Naier-Stokes's equation are respectively used to characterize the flow in confined aquifer and tunnel. The variation characteristics of velocity, pressure and discharge on different position of the fault have been analyzed. In addition, the permeability effect of water inrush on different faults has been modeled. It has been found that risk of water inrush becomes higher for obvious pressure relief resulting from increasing permeability.