A Study on the Impacts of One-Strut Failure Scenarios for Deep Excavation in Loose to Medium-Dense Sand

Abstract

This study aims to identify the impacts of one-strut failure (OSF) during deep excavation in loose to medium-dense sand with respect to strut loads and wall deflections. The finite element software PLAXIS was used to carry out both 2D and 3D analyses. In addition, as two-dimensional (2D) analysis is commonly applied in engineering practice due to limited budget and time, the reasonable transferring of results obtained using 3D analyses to 2D analyses for OSF influences was explored. It was found that a failed strut located at the lowest level at the center of the excavation is the most critical case since it causes the most significant impacts on strut load transferring and additional wall deflection. In order to adequately demonstrate such impacts using 2D analyses, it is suggested that a reduction factor of axial stiffness of 2.5 should be adopted instead of removing an entire level of struts, as currently being used in 2D analyses of OSF.