2021 Volume 21 Issue 5 Pages 5_13-5_26
In the stability evaluation of ground for important structures such as nuclear power plants, the stress of the ground during an earthquake is calculated by two-dimensional FEM analysis, and the safety factor for slip is estimated from the driving stress and the resisting stress on the assumed slip lines. However, the setting of the slip line requires a lot of preliminary study and engineering judgements. Therefore, it is difficult to set the critical slip line, which has the minimum safety factor in complex ground models. In this paper, we developed a method to find the critical slip line using particle swarm optimization based on the stress of the ground evaluated by FEM analysis. This method is applicable to search the critical slip line through a discontinuity plane such as a fault plane. To confirm the validity of the method, searches are conducted for several geologic models, and the results are compared with previous studies and analyzed in detail. It is shown that the method enables searching the critical slip line appropriately and efficiently based on the result of FEM analysis in complicated geologic model including a discontinuity plane.
