Effect of Soil Classification on Seismic Behavior of SMFs considering Soil‐Structure Interaction and Near‐Field Earthquakes

Abstract

Seismic response of a structure is affected by its dynamic properties and soil flexibility does not have an impact on it when the bottom soil of foundation is supposedly frigid, and the soil flexibility is also ignored. Hence, utilizing the results obtained through fixed-base buildings can lead to having an insecure design. Being close to the source of an earthquake production causes the majority of earthquake’s energy to reach the structure as a long-period pulse. Therefore, near-field earthquakes produce many seismic needs so that they force the structure to dissipate output energy by relatively large displacements. Hence, in this paper, the seismic response of 5- and 8-story steel buildings equipped with special moment frames (SMFs) which have been designed based on type-II and III soils (according to the seismic code of Iran-Standard 2800) has been studied. The effects of soil-structure interaction and modeling of the panel zone were considered in all of the two structures. In order to model radiation damping and prevent the reflection of outward propagating dilatational and shear waves back into the model, the vertical and horizontal Lysmer–Kuhlemeyer dashpots as seen in the figures are adopted in the free-field boundary of soil. The selected near- and far-field records were used in the nonlinear time-history analysis, and structure response was compared in both states. The results obtained from the analysis showed that the values for the shear force, displacement, column axial force, and column moment force on type-III soil are greater than the corresponding values on type-II soil; however, it cannot be discussed for drift in general.

Seismic Performance of Steel Structure-Foundation Systems Designed According to Eurocode 8 Provisions: The Case of Near-Fault Seismic Motions

“…With notable exception that of the 1985 Mexico earthquake [2], the effect of SSI to steel structures subjected to far-fault seismic motions seems to be marginal. So far, only a few parametric studies have been carried out on the investigation of the effect of SSI to steel structures [3][4][5][6][7][8][9][10].…”

A Study on the Effects of Vertical Mass Irregularity on Seismic Behavior of BRBFs and CBFs

“…Shahbazi et al [55] studied the seismic behavior of special moment frames (SMFs) with special ductility undergoing near-and far-field earthquakes by considering different modes, including the effects of soil-structure interaction, permanent displacement (Fling step), and forward directivity in near-field earthquake records, as well as vertical component of near-field earthquakes. It was demonstrated that near-field earthquakes impose more damage on the structure than far-field earthquakes [56][57][58].…”

Seismic Response of Steel Moment Frames (SMFs) Considering Simultaneous Excitations of Vertical and Horizontal Components, Including Fling-Step Ground Motions

“…The live and live loads of 20 kN/m 2 and 65 kN/m 2 , respectively [36], were applied to all stories. But different loads were applied for roofs, at 54 kN/m 2 and 15 kN/m 2 , respectively [26,37]. All models were fulfilled based on the rigid bed which was used for all stories.…”