SGER: Seismic Performance of Suspended Piping Systems - from the Field to the Laboratory, CMS proposal 0500225
PI: Tara C. Hutchinson, UC-Irvine
This small grant for exploratory research (SGER) is requested as a small extension to an existing field experiment project conducted on a full-scale building structure in the Los Angeles area. In the field project, the dynamic response of a number of nonstructural elements within the building of interest were measured during simulated seismic and other transient loading cases. Loading for these experiments was provided by mass eccentric and linear shakers mounted on the roof of the building. Of particular interest during the experiments was the in-place dynamic characterization of suspended piping systems. Limitations in the shaker systems prohibited larger than approximately 0.3g input motions into the structure. Subsequent to field testing, a number of suspended piping systems were removed from the building and collected for future characterization tests in the laboratory. To broaden the parameter space of suspended piping system dynamic response data, a small laboratory shake table testing program is proposed herein to capitalize on this available piping hardware, instrumentation from the previous field experiments, and all associated mounting hardware. In addition, a suitable diaphragm structure from previous nonstructural experiments conducted at UC Irvine is available for these experiments, with minimal modifications required.
The proposed laboratory program will allow the study of suspended piping systems at full-scale, and considering large amplitude seismic loading. Four aspects will be investigated, that could not be studied in the field, in a systematic fashion: (i) varying piping layouts (straight, 45_bends, and 90_bends), (ii) liquid filled (and not), (iii) differential (versus not) input motions and (iv) type of suspension system (hung, braced, and ductility enhanced). The later parameter investigation will involve the exploratory development of a simple ductility enhancement device, placed at the suspension/brace hanger, to incorporate additional seismic energy dissipation capacity. This is envisioned to result in decreased acceleration demands along the pipe and particularly at its joints, where large demands observed in the past have resulted in fracture at bends. The explored solution will be of a practical, cost-effective nature, such as a simple yielding steel member.
