The addition of a rocking structural system will soften the connection between a foundation and superstructure and help the beam-column connections to become softer than typical ones. These structures, with the addition of rocking structural systems, follow the elastic gap opening mechanism to soften the structural seismic response. Post-tensioned energy dissipating devices and dampers are used in rocking systems to enable the structure to return to its initial position (self-centering) and to dissipate seismic energy, respectively. The current study investigated the use of a rocking shear wall system in steel moment-resistant and hinged frames and determined the amount of damage and the economic effects on the structures. For this purpose, 3D models of 3-, 9-, and 20-story SAC-project steel frames were modeled and validated according to FEMA-355C and then a hybrid rocking shear wall was added to them. The structures were designed and modeled according to common seismic codes and were analyzed using nonlinear time history when subjected to a series of records from FEMA-355C. The results showed that the use of a hinged frame attached to a rocking concrete shear wall (HFR) increased the fundamental period and inter-story displacement and decreased the amount of steel used in the 3-, 9-, and 20-story models compared to similar models with fixed connections in moment frames (MFR). The HFR shear wall models exhibited better seismic performance than MFR models, which increased their load-bearing capacity and reduced their weight, which reduced construction costs.
Studies have shown that the high cost of repairing damaged structures and the time it takes to rebuild them after an earthquake, especially in densely populated cities, impose severe financial and economic pressures on countries. To solve this problem, rocking systems were introduced as new systems to improve the seismic performance of structures. In these systems, the rocking wall is allowed to rock and elastic devices are used to provide self-centering and dissipate the seismic energy. The advantages of this system include low structural damages, ease in performing structural repairs as well as reducing the costs regarding them. In the current study, the geometry of an existing rocking shear wall attached to three- and nine-story moment-resisting frames was investigated by reducing the rocking wall’s thickness in height and also by adding border elements to the wall as dumbbells. The models were designed according to common seismic codes and then were analyzed through nonlinear time-history analysis when subjected to a series of modified near-field ground motions. According to the results, it was observed that besides exhibiting desired behavior through the combination of prestressed cables and energy dissipating elements, the modified rocking shear wall improved the performance level of the structures and reduced the amount of concrete used by 36 and 20% in 3- and 9-story models. The new system with a modified rocking wall had on average a higher fundamental period, higher base shear, and more properly distributed plastic hinges. This was because of less concrete usage, as well as deploying less prestressed cables compared to the conventional model.
The addition of a rocking structural system will soften the connection between a foundation and superstructure and help the beam-column connections to become softer than typical ones. These structures, with the addition of rocking structural systems, follow the elastic gap opening mechanism to soften the structural seismic response. Post-tensioned energy dissipating devices and dampers are used in rocking systems to enable the structure to return to its initial position (self-centering) and to dissipate seismic energy, respectively. The current study investigated the use of a rocking shear wall system in steel moment-resistant and hinged frames and determined the amount of damage and the economic effects on the structures. For this purpose, 3D models of 3-, 9-, and 20-story SAC-project steel frames were modeled and validated according to FEMA-355C and then a hybrid rocking shear wall was added to them. The structures were designed and modeled according to common seismic codes and were analyzed using nonlinear time history when subjected to a series of records from FEMA-355C. The results showed that the use of a hinged frame attached to a rocking concrete shear wall (HFR) increased the fundamental period and inter-story displacement and decreased the amount of steel used in the 3-, 9-, and 20-story models compared to similar models with fixed connections in moment frames (MFR). The HFR shear wall models exhibited better seismic performance than MFR models, which increased their load-bearing capacity and reduced their weight, which reduced construction costs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.