Evaluating Seismic Stability of Retaining Wall Heel Strengthened with Pre- Stressed Ropes using Kinematic Limit Analysis Approach

Abstract

Abstract To enhance the resistance against sliding and overturning in a cantilever retaining wall, the study introduces a heel plate at the base of the wall’s backside. This heel plate is designed to work with the wall's combined weight and the soil fill's weight placed on the heel plate. These components work together to mitigate the lateral forces produced by the soil fill. The objective is to efficiently and cost-effectively mitigate the seismic forces by integrating a cantilever retaining wall with a heel plate and pre-stressed rope, capitalising on the favourable seismic response characteristics. The study used the kinematical approach based on the upper bound theorem to examine the system's failure mechanism and critical yield acceleration coefficient involving a retaining wall, ropes, and soil. This framework identified two distinct failure modes: the long-heel baseplate failure mode and the short-heel baseplate failure mode. These failure modes were distinguished based on the second and third conditions for generating slip surfaces in the analysis. Assuming that the sliding surface of the backfill follows a straight line, this study applies the Mohr-Coulomb failure criterion to establish critical state equations of pre-stressed ropes in a retaining wall with a heel, considering two distinct failure modes. Seismic yield acceleration coefficients are derived for each failure mode. Utilising the extremum principle, the study offers an optimal solution, including determining the critical yield acceleration coefficient and the associated inclination angle of the backfill sliding surface.