The evaluation of the seismic performance of non-structural elements (NSEs) has gained special relevance in the last decades from the earthquake engineering community as a result of several aspects. The losses estimated following the seismic events that have occurred in urban regions in the last two decades, repeatedly showed that the NSE losses often exceed that of the structural components. This issue is partly due to the fact that the investment associated to the NSEs is on average higher than the cost of the structure, and partly due to the higher vulnerability of NSEs at lower seismic intensities if compared to their structural counterpart. Additionally, in the performance-based seismic design and assessment framework, the harmonization between the performance of both non-structural and structural elements plays a fundamental role, since a non-acceptable NSE performance level can completely compromise the global performance and functionality of a facility. Several methodologies have been developed to seismically design and analyze NSEs in the last decades. However, a complete comprehensive methodology to quantify the performance of NSEs is still not available due to the multitude of NSE typologies and to the difficulties to consider all the involved parameters, such as the prediction of a seismic demand representative of the different possibilities of building seismic-force-resisting systems (SFRSs) containing the NSEs. For building structures, the FEMA P695 methodology has been developed. It provides a standardized and objective methodology that defines how to calibrate seismic performance factors (SPFs), namely the response modification factor (R), the system overstrength factor (Ω0), and the deflection amplification factor (Cd), for new SFRSs proposed for inclusion in model building codes in the United States. Nowadays, a proper equivalent methodology for NSEs is not yet available. In this paper, a standardized framework to evaluate performance and quantify SPFs for new and existing NSEs systems is developed. The new information required to implement the proposed standardized framework is highlighted. An illustrative example of the proposed framework is provided in which the quantification of the behavior factor (qa) for suspended piping restraint installations designed according to Eurocode 8 is performed to meet various performance objectives. It is believed that the development of the proposed framework would provide higher uniformity in performance evaluation of NSEs, thereby providing a path in which designers, researchers and stakeholders can effectively evaluate, compare and even propose new NSEs components and systems and seismic design procedures for inclusion in model building codes
A framework for quantifying seismic performance factors for non-structural elements
Daniele Perrone;
2020-01-01
Abstract
The evaluation of the seismic performance of non-structural elements (NSEs) has gained special relevance in the last decades from the earthquake engineering community as a result of several aspects. The losses estimated following the seismic events that have occurred in urban regions in the last two decades, repeatedly showed that the NSE losses often exceed that of the structural components. This issue is partly due to the fact that the investment associated to the NSEs is on average higher than the cost of the structure, and partly due to the higher vulnerability of NSEs at lower seismic intensities if compared to their structural counterpart. Additionally, in the performance-based seismic design and assessment framework, the harmonization between the performance of both non-structural and structural elements plays a fundamental role, since a non-acceptable NSE performance level can completely compromise the global performance and functionality of a facility. Several methodologies have been developed to seismically design and analyze NSEs in the last decades. However, a complete comprehensive methodology to quantify the performance of NSEs is still not available due to the multitude of NSE typologies and to the difficulties to consider all the involved parameters, such as the prediction of a seismic demand representative of the different possibilities of building seismic-force-resisting systems (SFRSs) containing the NSEs. For building structures, the FEMA P695 methodology has been developed. It provides a standardized and objective methodology that defines how to calibrate seismic performance factors (SPFs), namely the response modification factor (R), the system overstrength factor (Ω0), and the deflection amplification factor (Cd), for new SFRSs proposed for inclusion in model building codes in the United States. Nowadays, a proper equivalent methodology for NSEs is not yet available. In this paper, a standardized framework to evaluate performance and quantify SPFs for new and existing NSEs systems is developed. The new information required to implement the proposed standardized framework is highlighted. An illustrative example of the proposed framework is provided in which the quantification of the behavior factor (qa) for suspended piping restraint installations designed according to Eurocode 8 is performed to meet various performance objectives. It is believed that the development of the proposed framework would provide higher uniformity in performance evaluation of NSEs, thereby providing a path in which designers, researchers and stakeholders can effectively evaluate, compare and even propose new NSEs components and systems and seismic design procedures for inclusion in model building codesI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
