SEISMIC PERFORMANCE CHARACTERIZATION OF FIRE SPRINKLER PIPING SYSTEMS THROUGH SHAKE TABLE TESTING.

Fire sprinkler systems damaged during earthquakes can compromise the functionality of a building facility either by loss of fire protection and/or by damage due to flooding. Shake table tests were conducted on a sprinkler piping specimen, with features representative of actual practices in New Zealand, to characterize its dynamic behavior under seismic floor excitation. The aim of the testing was to signify the need for a reliable procedure in the relevant New Zealand Standard (NZS 4541) for the estimation of seismic demands on these systems. The specimen was subjected to a set of motions including recorded floor acceleration response histories of an instrumented building in New Zealand. This paper first describes the test setup and the piping specimen and then discusses the seismic response of the specimen to multiple floor motions for different bracing variations. The testing showed that bracing segments of piping other than the distribution pipe modifies the dynamic characteristics of the system and consequently the seismic demands. The test results further confirm that seismic demands on pipes can be considerably greater if the system is in resonance with the floor excitation. Recommendations are provided for necessary improvements to NZS 4541 (2020) for a reliable estimation of seismic demands. [ABSTRACT FROM AUTHOR]