Probabilistic collapse assessment of steel frame structures considering the effects of soil-structure interaction and height

Abstract

This paper investigates the seismic performance of Intermediate Moment-Resisting Steel Frame structures considering the effects of height and soil-structure interaction. For this purpose, three 3D structures of 3, 6 and 9-storey were designed using CSI ETABS software in accordance with ASCE7-16. Then the 2D frames of the structures were simulated by OpenSees software and to account for the nonlinearity of the material, the plastic hinge elements were used. The 2D frames were analyzed using IDA method subjected to 22 far-field ground motion records of FEMA-P695. Finally, the fragility curves of the structures were developed. The results showed that consideration of soil-structure interaction leads to lower spectral acceleration as height increases, meaning that higher-rising structures have record-induced S a(T1,5%) closer to S a(Design) , and with decreasing height the difference tends to increase. Exceedance probability decreases with the increase of structure's height and soil-structure interaction consideration adapts to lower exceedance probability. Also, the investigated Intermediate Moment-Resisting Steel Frame structural models designed according to ASCE7-16 consideration showed to have acceptable seismic performance against far-field records indicating that their exceedance probability in terms of the LS and CP performance level respectively are less than 0.45 and 0.03.

The Effect of Soil-Structure Interaction (SSI) on Structural Stability and Sustainability of RC Structures

“…Additionally, pier column non-linearity had a greater impact on base stress and bridge displacement than SSI did. The impact of foundation rocking on bridge response variables has also been a factor of investigation owing to the high rocking impedance of correctly built bridge foundations, [80].…”

Seismic performance assessment of intermediate moment-resisting steel frames designed based on misidentified site soil classes

“…In this study, three models of 3-, 6-, and 9-storey were designed by CSI ETABS 2016 [36] according to the method of LRFD and based on ASCE7-16 consideration [34] with modification factor 4.5 (R=4.5) and impotence factor 1 (I=1). Designed models are the same as the ones used previously in another research paper of the authors [23]. The models were designed for a region with very high level of seismic intensity (Risk Category II and Seismic Design Category D) with parameters S s =1.5 and S 1 =0.6.…”

“…Also, during the design procedure, at the bottom of columns in ground zero elevation, the restraining condition is considered as rigid connections, and after extracting detailed forces of the structure, footings of the models were designed separately as strip foundations. Figure 1 presents the structural plan and 3D view of the investigated models [23].…”

“…Subsequently, by plotting the graphs of intensity level versus response and applying limit states, the assessment of the structure can be accomplished. Using this type of analysis enables the engineers to assess the structural behaviour of the models from linear elastic to nonlinear inelastic phase through a step-by-step process which results in a precise approximation of the seismic safety of the investigating structural models [23].…”

“…Previously accomplished investigations emphasize the essential role of flexible foundations in the structural design of buildings [23]. These researches showed that consideration of SSI in site soil class of C adapts to lower exceedance probability and the soil shear modulus was identified to be much affecting the fragility curves [24,25].…”