Report - PEER - University of California, Berkeley

The development of next-generation guidelines for the ATC-58 project iscurrently planned to occur in two phases. The first phase comprises development ofbuilding performance assessment guidelines. In a major departure from priorperformance based approaches, rather than expressing performance in terms ofarbitrary performance levels, the next-generation procedures characterizeperformance directly in terms of the probable loss of life, repair costs andoccupancy/functionality interruptions times resulting from earthquake damage. Theevaluation procedures closely follow the framework for performance-basedearthquake engineering developed by the Pacific Earthquake Engineering ResearchCenter (PEER) in which probable earthquake losses are calculated by integrating overthe ground shaking hazard, probable structural response given the ground motionintensity, probable damage levels given the structural response and probable lossgiven damage (Deierlein, 2004). In the second phase, performance-based designprocedures will be developed to allow engineers to efficiently determine appropriatecombinations of structural stiffness, strength and ductility, as well installationprocedures for nonstructural components to achieve various levels of performancecapability. Stakeholders’ guides will be developed to assist in selecting appropriateperformance objectives as the basis for building development projects.Details regarding the background, budget and schedule of the ATC-58 projectalong with a description and example illustrations of the general methodology of thenext-generation guidelines are provided in a companion paper in this conference(Hamburger, 2004). The remainder of this paper will focus primarily on the plan fordeveloping the first phase performance assessment guidelines for nonstructuralcomponents for the project. The term nonstructural components covers a wide rangeof items that include all items in a building other than the building structural systemand its foundation. Nonstructural components include all architectural elements suchas cladding, glazing, ceiling systems and interior partitions that are permanentlyattached to the building. Nonstructural components also include all mechanical andelectrical equipment such as fire sprinkler systems, water and sewer piping, HVAC(heating, ventilating and air conditioning) systems and electrical distribution andlighting systems that are permanently attached to the building. Nonstructuralcomponents may also include building contents such as furniture, movable partitions,computers, movable equipment and merchandise.2. PERFORMANCE ASSESSMENT PROCESSThe performance assessment process, illustrated in Figure 1 below, begins withdefinition of one (or more) ground motion Intensity Measures (IMs) that shouldcapture the important characteristic(s) of earthquake ground motion that affect theresponse of the structural framing and nonstructural components and buildingcontents. The IM, which for the building structural system may be a ground motionparameter, such as peak ground acceleration, peak ground velocity, peak grounddisplacement, a spectral response quantity such as spectral displacement, velocity or127