Optimum Load and Resistance Factors for External Seismic Stability of Reinforced Soil Walls: A Reliability Based Approach

摘要

The paper presents a framework for calculating the resistance and load factors for the design of reinforced soil walls (RSW) by considering the potential failure mechanisms, i.e. sliding failure, eccentricity failure of resultant force and bearing capacity failure. Target reliability based approach (TRA) is used to determine the appropriate ranges for the values of the load and resistance factors. Using pseudo-static limit equilibrium method, analysis is conducted to evaluate the external stability of reinforced soil walls subjected to earthquake loading. The work described herein is largely consistent with the existing Federal Highway Administration (FHWA) specifications for new design of mechanically stabilized earth walls including AASHTO LRFD Bridge Design Specifications. Resistance and load factors are calibrated to meet five possible target reliability indices 2.0, 2.5, 3.0, 3.5 and 4.0 against three modes of failure for various values of coefficients of variation (COV) of friction angle of backfill and horizontal seismic acceleration coefficient.