1D Seismic Response Analysis of Soil-building Systems Including Failure Shear Mechanisms

Modelling of soil shear rupture due to an earthquake is not generally implemented in the common codes for 1D seismic response analysis. It requires the use of advanced plasticity-based constitutive models of soil, that are often neglected in practice. A good balance between simplicity and reliability can be achieved with methods based on simplified formulations of the mathematical equations and of the constitutive models. The paper presents a computer code based on this philosophy conceived, addressed and optimised to reliably model both the 'transient' seismic response ('stick' mode) and the permanent deformation mechanisms accounting for the coupled effects of deformability and strength ('slip' mode). The code can be adopted to evaluate the seismic performance of different geotechnical systems that can be reasonably approximated to a 1D problem. In the paper, the code is applied to model a soft-storey failure occurred in a framed structure heavily damaged during a strong-motion earthquake.