Report - PEER - University of California, Berkeley

4. Develop standard procedures including testing protocols for quantifying theperformance capabilities (fragility and loss functions) for the various typesof components and systems.5. Develop a framework for adjusting the generalized fragility and lossfunctions with available and more accurate and reliable fragility and lossfunctions for specific components and systems obtained by testing, analysisor empirical observations.6. Development guidelines describing the Performance Assessment Procedureand provides examples which illustrate usage of the procedures.In the remaining portions of this section, the above tasks are described in moredetail.3.1 Identify Nonstructural Engineering Demand ParametersTraditional nonstructural engineering demand parameters (EDP-Ns) found in currentcodes and first generation performance based guidelines are limited to componentforces and for some limited cases interstory relative displacement (drifts). Componentforce demands are determined by applying a lateral load to the center of mass of thecomponent and then typically computing the forces in the component’s bracing andattachments. Some nonstructural items such as cladding are specifically designedusing interstory drift as the EDP-N. Typically, drift demand for cladding wasdetermined based on the maximum drifts permitted for the structural system and noton the actual computed drift for the specific structure. Internal member forces causedby or imposed by interstory drifts were then added to the forces resulting from otherloadings when drift was a consideration. In code-based designs and presentperformance based design guidelines, nonstructural component design forces arecalculated using indirect and imprecise procedures based on empirical relationships.Therefore the result is traditional EDP-Ns do not necessarily correlate well withobserved damage of nonstructural components in earthquakes.For the next generation performance based engineering guidelines, an importantcriteria in the selection of EDP-Ns will be the correlation of EDP-Ns with damage. Itis desirable for the EDP-Ns to be both useful and efficient. For an EDP-N to beuseful, it must be compatible with the structural analysis or testing protocol which isused evaluate the nonstructural component response. An EDP-N is efficient if thevariability associated with prediction of response and associated tend to be small. Inthis task, EDP-Ns of significance will be identified. The primary focus initially willbe to identify EDP-Ns that are directly associated with building response motionssuch as interstory drift and peak floor acceleration. Other building response motionsthat are likely to be of significance include spectral acceleration of the floor at thefundamental period of the nonstructural component. A plot of a 5% damped roofresponse spectra and ground response spectra measured in a 19 story building duringthe Northridge earthquake is shown in Figure 2. It should be noted that the roof130