Influence of foundation flexibility on the seismic response of low-to-mid-rise moment-resisting frame buildings

Abstract

Abstract. Recent studies have shown that the e ects of Soil-Structure Interaction (SSI) may be detrimental to the seismic response of structure, and the neglect of SSI in analysis may lead to an un-conservative design. The objective of this study is to simulate the performance of multi-storey building-foundation systems through a Winklerbased approach. Four typical steel Moment-Resisting Frame (MRF) buildings on three soil types with shear wave velocities of less than 600 m/s subjected to actual ground motion records of varied hazard levels are modeled with and without SSI. It is observed that the performance level of models supported by exible foundation, particularly in an intense earthquake event, may alter signi cantly in comparison to xed-based structures. Moreover, for MRFs on soft soil, the nonlinear foundation is found to have a signi cant e ect on the force and displacement demands. This indicates the necessity for consideration of exible foundation behavior in the modern design codes in order to accomplish a more economic yet safe structural design.

Effect of Foundation Flexibility on the Seismic Performance of a High-Rise Structure under Far-Field and Near-Field Earthquakes

“…FLAC 2D nonlinear environment was used to model the near-reality behavior. The results of modeling were compared with the simplified nonlinear model of Tahghighi and Rabiee's research results [5]. The modeling steps are as follows: first, the soil layers were modeled according to Mohr-Coulomb behavioral model [25] using FLAC software, and then the strip foundation and the main structure were modeled.…”

“…However, for moment-resisting frames on soft soils, flexible foundations have a significant effect on displacement and force responses. This indicates the need to pay more attention to the behavior of flexible foundations in modern design in order to achieve more economical and safer structures [5]. Choosing the right type of foundation can significantly affect the response of the structure and the foundation of the building [6].…”

Investigating the Performance of Isolation Systems in Improving the Seismic Behavior of Urban Bridges. A Case Study on the Hesarak Bridge

“…In other words, it is assumed that the foundation of the bridge is fixed against all the movements. It is worth mentioning that Tahghighi and Rabiee [19] concluded that ignoring base flexibility may over or under predict seismic response of the structure depends mainly on the soil-structure relative rigidity. Therefore, the soil-pile-bridge interaction should be considered as a further study on the seismic response of the bridge.…”

Numerical comparison on the efficiency of conventional and hybrid buckling-restrained braces for seismic protection of short-to-mid-rise steel buildings

“…As a result, the assessed seismic evaluation of the buildings only relies on the superstructures. This approach is useful and straightforward, but the flexibility of the foundation has to be considered; otherwise, the dynamic characteristics and seismic performance of structures may be considerably diverse from those of the real demands (Tahghighi and Rabiee 2017;Wolf 1985). Therefore, investigating the effect of foundation flexibility on the seismic behavior of steel braced frame structures is required as a further study.…”