Seismic response evaluation of medical gas and fire-protection pipelines' Tee-Joints

In a life-safety view, medical gas and fire-protection piping systems are supposed to be the categories which require a special attention, since their functionality is often fundamental even in case of earthquake. The seismic behaviour of fire- protection and medical gas piping systems is analysed in the present work through experimental tests on T-joint connections, which are the most vulnerable components in case of earthquake. Quasi-Static cyclic tests were performed to define the hysteretic response of cast-iron and copper joints, in terms of Force-displacement and Moment-rotation behaviour. To the best of the author's knowledge no studies have been conducted yet on copper joints, while the results obtained from the tests on steel joints were compared with results available in literature. Furthermore, the influence of the fitting on the response in case of threaded connection was investigated. The results obtained have been adopted to calibrate simplified numerical models aimed at simulating the cyclic response of the components analysed. The proposed models would be useful in numerical analyses for the vulnerability assessment of piping systems layouts.