Fragility Assessment of Typhoon-Induced Hazard to Roof Sheathing Panels of Low-Rise Building

Abstract

Because of the vulnerability of roof sheathing panel to wind load, light-frame wood low-rise buildings often suffer from serious destructions in typhoon hazards. Efficient assessment of these hazards is an urgent need for the purpose of risk mitigation. The paper develops a database-assisted fragility approach for the assessment of typhoon-induced hazards to low-rise building roofing. In the developed approach, the failure of a single panel and the damage ratio of the entire roof over the typhoon duration are formulated in a probabilistic way where the dependence among wind loads is considered. Via the probabilistic formulation, the holistic analysis for typhoon-induced hazards to low-rise building roofs is decomposed to the hazard analysis at each individual time step. An analytical solution is proposed to determine the failure probability of each single panel and the probability related to the associated failure of each pair of panels at each time step. For a single panel, its failure probability is estimated by applying the Hermite transformation to the limit-state function. For the associated failure of each pair of panels, Nataf transformation is used to model the dependence between the limit-state functions of two panels. Wind field data recorded during the historical typhoon Hagupit are used to illustrate the effectiveness of the approach. Through this approach, the damage progress on roofs is revealed and the influence of wind loading dependence is investigated.