System probabilistic serviceability assessment of braced excavations in clays

Abstract

The system probability of serviceability failure for braced excavations in clays is investigated in this paper. The serviceability assessment involves the potential damage to the adjacent infrastructures caused by the excessive wall deflection and the associated ground surface settlement. In this study, the finite element program of PLAXIS implemented with user-defined soil models is adopted as a tool to simulate the excavation-induced wall deflection and ground surface settlement. The performance functions for both wall deflection and ground surface settlement are constructed through response surface method (RSM). Depending on the limiting excavation-induced responses, the serviceability limit state (SLS) design can be realized through meeting the acceptable system reliability or the corresponding system probability of serviceability failure. A case study is presented herein to demonstrate the feasibility of the system reliability approach in the design of braced excavations.