A Comprehensive Finite Element and Reliability-Based Analysis of Hybrid Reinforced Earth Retaining Wall Stability and Deformation

This study investigates the effect of design parameters on the behaviour of a hybrid wall consisting of a mechanically stabilized earth (MSE) wall over a soil nail (SN) wall. A response surface was developed from the finite element analysis results to quantify the influence of parameter uncertainties on the behaviour of the hybrid wall. Two failure surfaces were identified: a global failure surface starting at the toe of the hybrid wall and passing through the SN wall and a linear failure surface extending externally behind the MSE wall. A tension crack zone was also identified adjacent to the end of soil nail reinforcement, which propagates upward into the MSE wall. The wall height and the reinforcement length of the MSE wall and SN wall significantly impact the hybrid wall’s stability. The friction angle of the MSE and SN wall soil, as well as the coefficient of variation of critical parameters, significantly affects the reliability of the hybrid wall. Reliability-based design charts were developed to empower the designer to achieve target reliability. These charts provide the required design ratio of the reinforcement length of the MSE wall to total wall height (L_MSE/H) for the critical parameters.