Experimental Seismic Fragility of Steel Studded Gypsum Partition Walls and Fire Sprinkler Piping Subsystems

Partition wall and fire extinguishing sprinkler piping nonstructural subsystems constitute a significant portion of the total investment in building infrastructure. Past earthquakes and numerical simulations have demonstrated that damage to these nonstructural subsystems can cause substantial earthquake losses and degrade the overall functionality of buildings. Nevertheless, the data obtained from field observations, previous experimentations, and numerical simulations are insufficient to fully characterize their mechanical response under seismic actions and to develop effective solutions to improve their seismic performance. As part of the NEES Nonstructural Grand Challenge Project: Simulation of the Seismic Performance of Nonstructural Systems an experimental program is underway to evaluate the seismic performance of full-scale light gage steel studded gypsum partition walls and fire suppression piping subsystems. Fifty partition wall specimens, corresponding to 22 wall configurations, were constructed following standard construction techniques typically used in commercial and institutional facilities. Quasi-static and dynamic tests were carried out to assess the in-plane and out-of-plane seismic performance of the gypsum walls. Testing of piping systems is ongoing with two of the most common joint configurations, tees and elbows, being tested to determine the moment and rotation capacities at which leakage or fracture occur. Subsequently, a full scale two-story subsection of a typical commercial fire suppression system will be tested under dynamic loading. This paper reviews the failure mechanisms observed in the walls and in the piping systems and the application of the ATC-58 framework to develop a seismic fragility database for gypsum partition walls and fire sprinklers. Further, the experimental observations are used to propose a set of innovative construction details and configurations that minimize the seismic damage in these subsystems.