Search

With the advancement of performance-based earthquake engineering (PBEE), the seismic performance of non-structural elements (NSEs) has gained special relevance. The harmonization of the performance of NSEs and of the seismic force-resisting system (SFRS) in a building is fundamental to the PBEE concept. To provide a consistent level of performance for force-based designed SFRSs, the FEMA P695 Methodology provides an objective framework. No equivalent procedure currently exists for NSEs. This paper develops a framework to quantify seismic performance factors for NSEs. An illustrative case study example is presented for the calibration of the behaviour factor for suspended piping seismic restraint installations. [ABSTRACT FROM AUTHOR]

Performance-based earthquake engineering requires the harmonization of performances between structural and nonstructural elements. This paper discusses the performance-based seismic design of nonstructural elements through a direct displacement-based methodology applicable to nonstructural elements attached to a single location in the supporting structure and for which damage is the result of excessive displacements. The fundamentals of direct displacement-based seismic design are presented along with a description of the modifications required for its application to nonstructural elements. As an example, the direct displacement-based seismic design of a suspended piping restraint installation is presented. The design approach is appraised by nonlinear dynamic time-history analyses. [ABSTRACT FROM AUTHOR]

Summary: The achievement of adequate performance objectives for buildings under increasing seismic intensities is not only related to the performance of structural members but also to the behavior of nonstructural elements. The need to properly design nonstructural elements for earthquakes has been largely demonstrated in the last few years and has become an important objective within the earthquake engineering community. A crucial aspect in the proper design of nonstructural elements is the definition of the seismic demand in terms of both absolute acceleration and relative displacement floor response spectra. In the first part of this study, relative displacement and absolute acceleration floor response spectra were computed for four reinforced concrete moment‐resisting archetype frames via dynamic time‐history analyses and were compared with floor response spectra predicted by means of two recent simplified methodologies available in the literature. It was observed that one of the existing methodologies is generally unable to predict consistent absolute acceleration and relative displacement floor response spectra. An improved procedure is developed for estimating consistent floor response spectra for building structures subjected to low and medium‐high seismic intensities. This new procedure improves the predictions of a relative displacement floor response spectrum by constraining its ordinates at long nonstructural periods to the expected peak absolute displacement of the floor. The resulting acceleration and relative displacement response spectra are then consistently related by the well‐known pseudo‐spectral relationship over the entire nonstructural period range. The effectiveness of the proposed methodology was appraised against floor response spectra computed from nonlinear time‐history analyses. [ABSTRACT FROM AUTHOR]

The seismic performance of non-structural elements is nowadays recognized to be a key issue in performance-based earthquake engineering. The knowledge of construction details within a building is of paramount importance in order to reduce uncertainties and improve the quality of the analysis and design, particularly in regards to non-structural elements. The use of Building Information Modelling (BIM) could represent a new frontier in the seismic design of non-structural elements by increasing the reliability of the seismic design and/or assessment. This study discusses the effectiveness of using Building Information Models in seismic design of non-structural building elements. A simple tool has been developed to perform automatically the seismic design of sway braces for pressurized fire suppressant sprinkler piping systems based on information extracted from a Building Information Models. The effectiveness of the proposed procedure was validated via a case study. [ABSTRACT FROM AUTHOR]

Performance-based earthquake engineering (PBEE) considers certain metrics to assess the seismic response of buildings, which integrate economic losses into the design process. PBEE requires the development and use of reliable nonlinear response analysis models to simulate the seismic performance of structures through collapse. The structural damage is assessed by evaluating physical damage caused by engineering demand parameters (EDPs), while the nonlinear numerical models are used to conduct dynamic analyses for varying levels of seismic intensity to compute the values of the representative EDPs. Accurate representation of structural members' stiffness and strength deterioration (hysteretic) parameters plays an important role into simulating dynamic response through collapse. These parameters' values are usually calibrated to a large number of experimental data. The development of a hysteretic parameter database for wood and steel diaphragm connectors is presented in this paper. The wood diaphragm connectors are commonly used in light-frame wood building construction for shear walls or roof diaphragms. The steel diaphragm connectors are used for building structures that incorporate steel frame roof diaphragms. The experimental data were used for quantifying the hysteretic parameters of two well-known nonlinear models considered into structural modeling as well as evaluating their energy dissipation properties. Case studies on the collapse performance assessment of a light-frame wood wall system and a low-rise building incorporating a steel roof system were conducted to demonstrate the usefulness of the diaphragm connector database. [ABSTRACT FROM AUTHOR]

With the development and implementation of performance-based earthquake engineering, harmonization of performance levels between structural and nonstructural components becomes vital. Even if the structural components of a building achieve a continuous or immediate occupancy performance level after a seismic event, failure of architectural, mechanical or electrical components can lower the performance level of the entire building system. This reduction in performance caused by the vulnerability of nonstructural components has been observed during recent earthquakes worldwide. Moreover, nonstructural damage has limited the functionality of critical facilities, such as hospitals, following major seismic events. The investment in nonstructural components and building contents is far greater than that of structural components and framing. Therefore, it is not surprising that in many past earthquakes, losses from damage to nonstructural components have exceeded losses from structural damage. Furthermore, the failure of nonstructural components can become a safety hazard or can hamper the safe movement of occupants evacuating buildings, or of rescue workers entering buildings. In comparison to structural components and systems, there is relatively limited information on the seismic design of nonstructural components. Basic research work in this area has been sparse, and the available codes and guidelines are usually, for the most part, based on past experiences, engineering judgment and intuition, rather than on objective experimental and analytical results. Often, design engineers are forced to start almost from square one after each earthquake event: to observe what went wrong and to try to prevent repetitions. This is a consequence of the empirical nature of current seismic regulations and guidelines for nonstructural components. This review paper summarizes current knowledge on the seismic design and analysis of nonstructural building components, identifying major knowledge gaps that will need to be filled by future research. Furthermore, considering recent trends in earthquake engineering, the paper explores how performance-based seismic design might be conceived for nonstructural components, drawing on recent developments made in the field of seismic design and hinting at the specific considerations required for nonstructural components. [ABSTRACT FROM AUTHOR]

A simple numerical model to predict the dynamic characteristics, quasistatic pushover, and seismic response of woodframe buildings is presented. In this model the building structure is composed of two primary components: rigid horizontal diaphragms and nonlinear lateral load resisting shear wall elements. The actual three-dimensional building is degenerated into a two-dimensional planar model using zero-height shear wall spring elements connected between adjacent diaphragms or the foundation. The degrading strength and stiffness hysteretic behavior of each wood shear wall in the building can be characterized using an associated numerical model that predicts the walls load-displacement response under general quasistatic cyclic loading. In turn, in this model, the hysteretic behavior of each shear wall is represented by an equivalent nonlinear shear spring element. With this simple approach the response of the building is defined in terms of only three degrees of freedom per floor. This numerical model has been incorporated into the computer program SAWS (seismic analysis of woodframe structures). This paper discusses model formulation. In Part II, the predictive capabilities of this program are compared with recent shake table tests performed on a full-scale two-story woodframe house. [ABSTRACT FROM AUTHOR]