Seismic Fragility Evaluation of Multi-Branch Piping Systems installed in Critical Low-Rise Buildings

The failure of nonstructural components such as piping, ceiling, mechanical and electrical equipments led to operational and functional problems in structural system during the past severe earthquakes. Consequently, in the last few decades, a reduction of the damage to nonstructural components or an improvement on the performance of nonstructural component has emerged as a key area of research. The primary objective of this research was to develop the seismic fragility of the piping system incorporating the multi T-joint branch piping systems. The procedure for evaluating fragility curves corresponding to the first damage limit state considered the effects of each floor acceleration-sensitivity for low-rise RC and steel frame building structures subjected to 50 selected ground motions as function of uncertainties. The result of this study revealed that the conditional probability of failure to the piping system on each floor level in critical facilities increased with increased level of floor and in fact, floor level in low-rise buildings can tune the fragilities between the building and the piping system.