Editors: | F. Kongoli, A. G. Mamalis, K. Hokamoto |
Publisher: | Flogen Star OUTREACH |
Publication Year: | 2018 |
Pages: | 352 pages |
ISBN: | 978-1-987820-88-1 |
ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
Nonstructural components and systems are defined as the elements of a building that are not part of its structural load-bearing system. However, these elements are subjected to the same dynamic environment experienced by the building caused by an earthquake. These systems represent over 75% of the loss exposure of US buildings to earthquakes, as they usually represent the major portion of the total investment in buildings. Furthermore, damage to nonstructural systems occurs at response intensities much lower than those required to produce structural damage. Therefore, it is not surprising that recent earthquakes have demonstrated that poor performance of nonstructural systems and components can result in significant damage. In the US they account for over 78% of the total estimated national annualized earthquake loss.
One of the major nonstructural systems in a building is the ceiling-piping-partition nonstructural system, which includes a key set of interconnected subsystems. These include different types of ceiling subsystems; complex floor-to-floor, in-floor, and in-ceiling water distribution piping subsystems with varying geometric configurations; specialized piping such as fire sprinkler subsystems; different types of partition subsystems; components such as pipe fittings, light fixtures, hangers, braces, valves and pumps; and HVAC components that affect the seismic response of ceiling-piping partition systems such as diffusers and ducts. The ceiling-piping-partition system is a very widely used nonstructural system that has been a main contributor to both seismic damage and associated property damage, functional loss, fire spread and hence casualty risks. All of its subsystems (i.e. piping, partitions and ceilings) have suffered significant damage in recent earthquakes. Such damage has resulted in property loss, loss of function, increased fire hazard and loss of life and has compromised the seismic resilience of communities.
This presentation summarizes damage of nonstructural systems in recent earthquakes and its impact on all categories of seismic risk and discusses the importance of these elements on the functionality of buildings. Furthermore, it presents major experimental and analytical research studies on the seismic response of these elements that were performed as part of an NSF NEESR Grand Challenge research project on this topic. This Grand Challenge project integrated multidisciplinary system-level studies that developed, for the first time, a simulation capability and implementation process for enhancing the seismic performance of the ceiling-piping-partition nonstructural system. It included a comprehensive experimental program that used the University of Nevada, Reno (UNR) and University at Buffalo (UB) NEES Equipment Sites as well as the E-Defense facility in Japan. A series of component- level experiments were performed initially t UB. Then a series of comprehensive system-level experiments, including several interacting components and sub-systems were performed at UNR. Finally, system level experiments using a full-scale 5-story building were performed at the E-Defense facility in Japan. Integrated with this experimental effort was a comprehensive numerical simulation program that developed experimentally verified analytical models and system and subsystem fragility functions.