RELIABILITY ANALYSIS OF SEISMIC STABILITY OF UNSATURATED SOLDIER-PILED EXCAVATION

Seismic stability analysis is an important aspect of the design of safe retaining walls in earthquake zone areas. The dynamic stability analysis of retaining walls is often conducted by the traditional method of slices, using pseudo-static calculations. The pseudo-static finite element approach which can accurately model the in situ stresses prior to seismic loading is relatively simple and not as computationally expensive as the time-domain approach. On the other hand, the stability of excavation is closely related to the variation of soil properties and matric suction. Moreover, Failure mechanisms of soldier piled-excavation are generally unidentified prior to stability analysis. Numerous limit states (e.g., external, serviceability and structural) can be supposed, cause several failure modes of soldier piled-excavation (e.g., global, lateral deflection, bending moment and shear). In most of the previous studies, one failure mode is considered or unsaturated state and variation of soil properties are neglected. To address these issues, this paper provides a probabilistic framework with random finite element-based program coded in MATLAB to evaluate the seismic stability of soldierpiledexcavation with consideration of inherent uncertainty of soil properties and unsaturated state. Results of numerical simulation show that neglecting the seismic loads lead to overestimate reliability parameters