Effect of cyclic loading protocols on the experimental seismic performance evaluation of suspended piping restraint installations

Suspended non-structural elements, such as water and sprinkler piping systems, are key to the functionality of important facilities, such as hospitals and schools. Recent earthquakes have demonstrated the vulnerability of these systems, particularly for those that were inadequately restrained. Seismic qualification requirements of non-structural elements contained in recent building codes and industry standards rely on experimental procedures, such as quasi-static cyclic testing of components and sub-assemblies. When conducting such quasi-static testing, the question arises as to what proper loading protocol to use. The first part of this paper reviews and compare existing cyclic loading protocols for testing various types of components and sub-assembles and developed according to scientific methods, including two specifically developed for testing non-structural elements. These two non-structural loading protocols are then used for conducting quasi-static cyclic testing of common components part of piping restraint installations. Characteristic response parameters resulting from test results with each cyclic loading protocol are extracted and compared. Observations and recommendations are provided on the effects of using different cyclic loading protocols for the performance evaluation and seismic qualification testing of suspended piping restraint installations.