System-Level Experiments on Ceiling/Piping/Partition Systems at UNR-NEES Site

Abstract

Many of the critical facilities and buildings, like hospitals and fire stations, need to be used immediately after earthquakes. However, seismic damages to ceiling-piping-partition systems (CPP) result in many cases in prolonged loss of function as seen in previous earthquakes. Moreover, the damage resulted in injuries and loss of property. As part of the project titled “NEESR-GC: Simulation of the Seismic Performance of Nonstructural System” a series of system-level large-scale experiments were conducted at UNR-NEES site from December 2012 to April 2013. These experiments attempted to investigate the system-level response and failure mechanisms of nonstructural systems including steel studded gypsum partition walls, suspended ceilings and fire sprinkler systems. The results also show how these subsystems interact among themselves as well as with the structural system of a building. For this purpose, a Test-Bed structure (a two-story, 2-bay by 1-bay steel frame system) was designed and constructed to simulate the realistic dynamic environment for the CPP systems. This structure was mounted longitudinally over three bi-axial shake tables. Looking at technical documents and major manufacture‘s catalogs, in addition to the general details currently in use in construction, different variables that could affect the seismic performance of CPP systems were identified. Combining these variables, a total of fifteen different configurations of suspended ceiling systems; two configurations of piping systems and more than 380 linear feet of partition walls were designed and installed in Test-Bed. These experiments led to valuable data including comparison between 1) different top connection details that comprised of full connections, slip-tracks, and innovative connections, 2) commercial and institutional corner connection details, 3) full height, self-supported partial height, and braced partial height partitions, 4) shaft wall and typical gypsum board partitions, 5) partitions with various opening sizes and directions of testing, 6) ceiling systems within a large and small area, 7) performance of the seismic clips and pop rivets in the perimeter ceiling grids, 8) ceiling systems with and without bracing elements. They also helped to investigate: 1) performances of different piping drop and branch lengths, 2) comparison of responses between conventional piping arm over drops and flexible hose drops, 3) performances of piping rigid braces and diagonal wires, 4) the effect of a 2” gap around the sprinkler head versus no gap during the interaction between piping and ceiling systems.