Model experiment and numerical analysis of horizontal subgrade reactions acting on flexible walls

Abstract

A method of reinforcing breakwaters with piles has been proposed. In this structure, designing piles as passive piles is important. Although most previous studies on horizontal subgrade reactions have been limited to the deformation mode of walls, the subgrade reaction to the wall is known to depend on the deformation mode of the wall. Herein, we investigated the changes in the subgrade reaction due to different deformation modes of the wall using model loading experiments and finite element analysis. The model ground was simulated using an aluminum rod mass, and an aluminum plate was used for the wall model. The model ground height was set to the horizontal ground condition with a 200 mm step at the front and rear of the wall. Lateral loads were applied simultaneously to the wall at two different depths. By controlling the ratio of the two levels of the lateral load applied to the wall, the deformation mode of the wall was altered. The experimental results indicated that the magnitude of the subgrade reaction at the same deflection depended on the deformation mode of the wall. The elastoplastic finite element analysis results of the lateral pile-head loading experiment in the horizontal ground condition exhibited good agreement with the experimental results. Under the two-point loading condition, the behavior of the wall was significantly different for cases in which the deformation mode differed from that of the lateral pile-head loading condition. By comparing the behavior of the ground around the wall, we discovered that the shear deformation of the ground differed depending on the deformation mode.