Fragility Analysis of Seismic Response of Cantilever Retaining Walls with Cohesive and Cohesionless Backfill Materials

In this investigation, fragility analysis of a cantilever retaining wall with a height of 6-m and cohesionless and cohesive backfills is conducted to evaluate the probability of failure due to earthquake peak ground acceleration (PGA). Calibrated seismic analyses of retaining walls are conducted using the finite difference method. Seven different earthquake ground motions are used to assess the seismic behavior of retaining walls under different earthquake conditions. The maximum relative displacement of retaining walls was determined for models with various earthquake loads as well as different backfill materials. Consequently, fragility analyses are conducted to determine the effect of earthquake intensity in terms of PGA and backfill cohesion on the failure risk of the retaining wall. Fragility results are provided based on probability curves demonstrating the likelihood of different levels of damage in a given earthquake PGA for various backfill cohesions. According to the fragility analysis, with consideration of 50% as the probability of failure, the threshold PGA free-field of the failure zone is 0.47 and 0.75 g, respectively.