New lateral load distribution pattern for seismic design of deteriorating shear buildings considering soil-structure interaction

Abstract

The current code-conforming seismic lateral load patterns are implicitly derived based on the dynamic solutions of fixed-base elastic structural systems, without considering the effects of hysteretic characteristic and soil-structure-interaction (SSI). Consequently, such lateral force patterns may not be applicable for the seismic design of nonlinear deteriorating structural systems. In this study, the analytical model was constructed using the shear building model. The peak-oriented modified I–K model and sway-rocking (S-R) model were employed to simulate the deteriorating behavior and SSI effects, respectively. A practical optimization design procedure for optimal lateral load pattern was developed based on the uniform damage distribution. The influence of main parameters on the new lateral load pattern was comprehensively investigated, including the parameters of the S-R model and the peak-oriented modified I–K model, ground motion excitations, fundamental period, target ductility, damping ratio and so on. The quantified expression of the new lateral load distribution was proposed as a function of fundamental period, the target ductility, aspect ratio and shear wave velocity. The results show that the structures designed according to the proposed lateral force pattern experienced obviously less damage than the code-conforming pattern.