Improving seismic behaviour of core walls of dual structural systems using multi-plastic hinges.

This paper studies the implication of the development of shear wall plastic hinges in high-rise dual systems. Multi-plastic hinge approach is intended to reduce the effects of higher modes of vibration in tall structural walls under earthquakes. This research investigated analytically the seismic response of three code conforming designed buildings with 16, 27 and 45 stories. These buildings which consist of a core wall/special moment frame dual system are modeled with four different approaches with single, dual, three and four plastic hinges, and some main structural responses including moment and shear distribution and values, drift ratio distribution and values, floor accelerations, contribution of frame in dual system and finally energy dissipation among plastic hinges are assessed. Findings of this research show that the application of multi-plastic hinge approach in wall design can properly affect seismic behavior of core walls and leads to improvement of system seismic capacity and economy of design. The investigation also shows that the application of multi-plastic hinge design concept can cause better use of frame nonlinear deformation capacity which would help better control of effects of higher modes. Based on analyses results, more frame contribution and improvement of wall behavior is observable in models with three and four plastic hinged walls in comparison with single plastic hinge model designed based on ACI 318-14 provisions. [ABSTRACT FROM AUTHOR]