Earthquake Protection of Residential Buildings: New Resilient System for Light Timber Framing

Abstract

In NZ, similar to other countries, residential houses are mostly constructed using light timber framing. The common seismic solutions available in the market for such low-rise buildings are based on yielding of sacrificial elements (such as nails or hold-down brackets) which will get damaged during an event. As a result, after a severe earthquake, repairs or replacement of parts will be needed which incurs costly post-event recovery as well as the vulnerability of the occupants given the risk of the aftershocks. In addition, due to the damage in the system, there would be loss of building stiffness and potentially a residual drift in the building. In this paper, a new seismic solution is presented specifically designed for the residential applications addressing the shortcomings of the current solutions. The system incorporates a new damage-free cylindrical friction damper with self-centring capacity which is combined with tension-only straps. This new system provides an easily installed, cost-effective seismic solution for residential buildings which have been less regarded compared to commercial structures though the earthquake impact could be even more crucial given directly affecting the residents and the families in the community. The paper will present the results of the Pushover analyses and the hysteretic performance of the system validated through full-scale testing. Also, the Bracing Units for the system is provided as per the P21 guidelines demonstrating the high efficiency of this system. This new seismic solution could be also applicable for retrofitting of earthquake-prone residential buildings.