Effects of soil‐structure interaction and lateral design load pattern on performance‐based plastic design of steel moment resisting frames

Abstract

Summary The effects soil‐structure interaction (SSI) and lateral design load‐pattern are investigated on the seismic response of steel moment‐resisting frames (SMRFs) designed with a performance‐based plastic design (PBPD) method through a comprehensive analytical study on a series of 4‐, 8‐, 12‐, 14‐, and 16‐story models. The cone model is adopted to simulate SSI effects. A set of 20 strong earthquake records are used to examine the effects of different design parameters including fundamental period, design load‐pattern, target ductility, and base flexibility. It is shown that the lateral design load pattern can considerably affect the inelastic strength demands of SSI systems. The best design load patterns are then identified for the selected frames. Although SSI effects are usually ignored in the design of conventional structures, the results indicate that SSI can considerably influence the seismic performance of SMRFs. By increasing the base flexibility, the ductility demand in lower story levels decreases and the maximum demand shifts to the higher stories. The strength reduction factor of SMRFs also reduces by increasing the SSI effects, which implies the fixed‐base assumption may lead to underestimated designs for SSI systems. To address this issue, new ductility‐dependent strength reduction factors are proposed for multistory SMRFs with flexible base conditions.

Seismic performance evaluation of masonry infill R.C. frame considering soil-structure interaction

“…Regardless of these findings, current research on SSI mainly focuses on structures with significant importance such as nuclear power plants, and study lacks in the field of commercial design approach of SSI [12]. Furthermore, the drift and ductility needs are distributed more uniformly along the height of the structures when SSI effects are taken into consideration since SSI can influence the yield mechanism of the prespecified plastic hinges in comparison to its fixed-base counterpart [13]. Thus, the effect of SSI seems to be rather significant relative to fixed-base where the translation along the structure's orthogonal axis and rocking interaction affects the response.…”

Soil-structure interaction in the performance-based seismic design of reinforced-concrete buildings

“…This factor, on the other hand, is defined as the ratio 𝑉 /𝑉 . Some studies have focused on the evaluation of these factors, as is the case of (Elnashai & Mwafy, 2002;Fernandez-Sola et al, 2014;Ganjavi et al, 2019;Louzai & Abed, 2015;Tahghighi & Mohammadi, 2020). Authors use models at different levels of sophistication with and without SSI effects considerations and are subjected to seismic actions to evaluate the behavior of 𝑅 and Ω factors.…”