CENTRIFUGE MODEL TESTS AND STRENGTH REDUCTION METHOD FOR INFLUENCE OF BENCH ARRANGEMENT ON STABILITY OF REINFORCED SLOPES

How to select the bench width of the stepped slope is still a topic of research. In this paper, centrifuge model tests and FEM-based strength reduction method are carried out to investigate the influence of benches on reinforced soil slopes with steps. The benches can be used to decompose the slope into several secondary slopes(steps). Centrifuge test results show that the damage of the slope is transferred to the steps of the slope, and the damage scale is reduced. Soil reinforcing can enhance the integrity of the slope as well as reduce the interaction between the steps. Benches with appropriate width can make the failure occur in the secondary slopes, which is helpful for the overall safety of the whole slope. The FEM numerical results show that the effect of cohesion can weaken when the slope is high enough. The benches divide the slope into several secondary slopes with lower height. As a result, the cohesion strength of the soil can be fully utilized in the stability of the slope. Since the effect of reinforcement is mainly to increase the apparent cohesion of the soil, the reinforced slope can be more stable with appropriate height of steps. For reinforced high soil slopes, the modulus and extensibility of reinforcement are key factors. The joint reinforcing effect cannot be mobilized if some reinforcements snap very early before others take effect.