Seismic Response of Secondary Systems Supported by Torsionally Yielding Structures

Abstract

Substantial damage sustained during several recent earthquakes was non structural in nature. The economic consequence in terms of non structural component damage far exceeded the structural damage. Currently, there are several analytical studies that address the interaction between non structural components or Secondary systems (S-systems) and the main supporting structure or Primary system (P-system). Only a few of these analytical approaches have been proposed to evaluate and characterize the response of the S-systems attached to torsionally coupled P-systems. In addition, the experimental verification for the analytical approaches is scarce.In the current study, the results and observations of an experimental research program conducted to characterize the behavior of both stiffness eccentric and mass eccentric torsionally coupled Primary-Secondary systems (PS-systems) are presented. From this experimental investigation it was found that the torsional yielding of the primary system has significant implications on the deamplification of near tuned secondary system response. The location of the S-system mounted on the P-system affects the peak response amplification, and interaction with the coupled P-system.

Effect of irregular structural configuration on floor acceleration demand in hill‐side buildings

“…A comprehensive state‐of‐the‐art review on the seismic design of NSCs in context of regular buildings has already been reported in earlier studies . Past studies on the evaluation of floor acceleration demands can be broadly classified under the categories of studies based on both single‐degree‐of‐freedom and multiple‐degree‐of‐freedom modeling of the supporting structure. The parameters affecting the floor response, identified in these studies, include the dynamic characteristics (periods and mode shapes) of the supporting structure, the input seismic ground motion characteristics, and the inelasticity (ductility demand) of the supporting structure .…”

“…Contrary to regular buildings, very few studies have focused on the floor response of irregular buildings . Mohammed et al carried out experimental investigations on NSCs mounted on stiffness‐ and mass‐eccentric torsionally yielding supporting structures, through shake‐table tests.…”

“…Mohammed et al carried out experimental investigations on NSCs mounted on stiffness‐ and mass‐eccentric torsionally yielding supporting structures, through shake‐table tests. It was reported that the torsional yielding of the supporting structure has significant implications on the deamplification of near‐tuned secondary system response . Aldeka et al studied the effect of ground type (site class) and eccentricity ratios on the seismic response of NSCs mounted on asymmetric inelastic RC buildings.…”

“…37,55,61 Contrary to regular buildings, very few studies have focused on the floor response of irregular buildings. [57][58][59][60] Mohammed et al 57 carried out experimental investigations on NSCs mounted on stiffness-and mass-eccentric torsionally yielding supporting structures, through shake-table tests. It was reported that the torsional yielding of the supporting structure has significant implications on the deamplification of near-tuned secondary system response.…”

“…It was reported that the torsional yielding of the supporting structure has significant implications on the deamplification of near-tuned secondary system response. 57 Aldeka et al [58][59][60] studied the effect of ground type (site class) and eccentricity ratios on the seismic response of NSCs mounted on asymmetric inelastic RC buildings. It was observed that the NSCs attached to the flexible sides of taller buildings were more affected by torsional behavior as compared with shorter buildings.…”