Seismic internal stability of bilinear geosynthetic-reinforced slopes with cohesive backfills

Abstract

The bilinear geosynthetic-reinforced slope (BGRS) is a new two-tier reinforced earth structure without an offset. Analyzing its seismic internal stability is aimed to determine the resultant reinforcement force. In this paper, using a top-down log spiral mechanism, the moment limit equilibrium equations are established to formulate the resultant reinforcement forces for upper and lower tiers of the BGRS, considering influence of angle of lower tier, depth of tension crack, cohesion of backfill and pseudo-static seismic loads. Results show that ignoring cohesion of backfill and/or vertical upward seismic load is beneficial to conservative stability analysis, and the existence of tension cracks changes the distribution of reinforcement forces in upper and lower tiers. Additionally, the critical slip surface is also studied, which is found that the volume of the failure body decreases under the global stability with increase of angle of lower tier, cohesion of backfill or depth of tension crack, or with the decrease of seismic coefficients.