Seismic Earth Pressure Reliability Analysis

This study examines seismic earth pressures in a typical retaining wall design. A reliability-based design is implemented to evaluate the influence of the uncertainty in the load and resistance. This reliability-based design includes; flexible and verifiable solution techniques, a simple means of comparing with factor of safety design, use of realistic probability distributions, proper modeling of correlation between parameters, and a practice-oriented spreadsheet solution. Reliability was calculated using first order reliability method (FORM) and Monte Carlo (MC) simulations. The results provide a means of evaluating the reliability of retaining walls subjected to seismic earth pressures, and also a means of assessing the probability of failure of existing walls that were designed without consideration of seismic earth pressures. For the gravity wall analyzed here, it was found that even though it was not designed to resist seismic earth pressures it still satisfies code-based stability requirements for peak ground accelerations up to similar to 0.46 g.