Shaking table tests on geosynthetic-reinforced soil retaining walls

Shaking table tests on geosynthetic-reinforced soil retaining walls (GRS-RWs) were performed on six models, varying the reinforcement length, height of embankment, type of the wall face, wall-surface gradient and input acceleration waveform, in order to observe the behavior and the reinforcing mechanism of GRS-RWs. The following results were obtained. By varying type of wall surface or wall-surface gradient, the slip surfaces took a similar shape, but the deformation form of the facing panels and reinforced soils was different in each case. Comparing the input acceleration required to cause the same amount of the wall displacement, the acceleration of the case subjected to seismic waves was larger than that of the case subjected to sinusoidal waves. When the model was vibrated with input acceleration large enough to induce residual deformation to the model, the amplitude of the response acceleration within the potential sliding block in the direction toward the back side of the embankment was smaller than that of the input acceleration. In the cases with discrete walls, both the earth pressure acting on the walls and the tensile force in reinforcement increased significantly at the bottom part of the embankment. In contrast, in the case with continuous facing wall, the increase was even through the depth. In the cases with vertical discrete walls, the earth pressure acting on the back side of the reinforced soil was responding with double the frequency of the input acceleration, when input acceleration became large. The plastic forward displacement of the walls developed when the input and response accelerations were directing backwards. It may be considered that the smaller peak corresponds to the active earth pressure state.