Coupled stress-flow simulations for the river levee considering overflow

Abstract

Recently, overflow due to the heavy rainfall causes the collapse of the river levee, as a result, serious flooding and damage. It is necessary to investigate the failure mechanism of the river levee due to the heavy rain and evaluate the stability of the river levee. According to the guideline for the design of the river levee, the seepage failure of the river levee is conventionally evaluated by the minimum safety factor of sliding, which is obtained from the circular arc calculation with the result of the seepage analysis. In this paper, the seepage failure caused by the overflow was mainly focused and simulated by newly developed coupled stress-water flow simulation code. In the numerical simulations, the seepage under saturated-unsaturated conditions considering rainfall, change of the water level, and overflow due to the heavy rain was solved and combined with the mechanical simulations. Stress and flow (seepage) were coupled only in the saturated zone and the coupled processes were not considered in the unsaturated zone. The simulation results clearly show the failure mechanism of the river levee by overflow.