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Special Interest
Page Contents Summary descriptive text (for detail, see Chapter 2 of the draft report). Summary of the methodological elements to be tested List of available data files Configuration. The UC Science Building testbed is a modern reinforced-concrete structure completed in 1988 to provide high-technology research laboratories for organismal biology. The building is 203,800 square feet overall, containing research laboratories, animal facilities, offices and related support spaces. The building is six stories plus a basement, and is rectangular in plan with overall dimensions of 306 feet by 105 feet. Structural system. The vertical load-carrying system consists of a complete reinforced-concrete space frame. The floor structure is a waffle slab on every level and is composed of a 4-½ inch thick reinforced concrete slab supported on 20-inch deep joists in each direction. The waffle slab is supported by reinforced-concrete girders, which in turn are supported by reinforced-concrete columns. The typical bay spacing is 20’-0” in the longitudinal direction and 22’-10” in the transverse direction. The foundations consist of a 38-inch deep continuous mat foundation. The lateral force-resisting system comprises reinforced concrete shearwalls in both directions. Elements of the Methodology Tested Here Overview. PEER researchers working on the UC Science Building testbed are focusing on estimating contents and equipment damage and the life safety and operational consequences of such damage. Other aspects of the PEER methodology, such as structural and architectural damage, collapse potential, repair costs and repair times, are the focus of the Van Nuys testbed. The performance estimation will entail evaluating the seismic hazard (including creation of a set of ground-motion time histories at three hazard levels), evaluation of engineering demand (displacements and accelerations), evaluation of contents and equipment damage, and evaluation of the potential for operational failure and life-safety threats. Intensity measures. Seismic intensity will be measured initially in terms of spectral acceleration (Sa). PEER researchers will also test alternative intensity measures (IM). The objective is to identify an IM that is more strongly correlated with performance, and whose occurrence rates can be readily calculated. That is, the new IM should reduce uncertainty on facility performance, conditioned on hazard level. We will elucidate and illustrate a methodology for calculating the probability (or possibly occurrence rate) p[IM]. Engineering demand parameters. PEER researchers will attempt to identify a limited set of engineering demand parameters (EDP) that are indicative of overall structural response, for use in simplifying design. It is hoped that a single parameter (or perhaps a small set) such as peak diaphragm acceleration at the top of the structure, will correlate strongly enough with performance that structural designers will not need to explicitly evaluate damage and loss, but merely demonstrate that EDP is less than some allowable level, associated with the desired level of performance. We will elucidate and illustrate a methodology for calculating the conditional probability p[EDP|IM], and given this and p[IM], the marginal probability p[EDP]. Damage measures. PEER researchers will create or compile fragility functions for the major damageable contents and scientific equipment of the building. Fragility functions give the probability of a facility component reaching or exceeding an undesirable performance level, as a function of excitation. PEER researchers will categorize the scientific equipment and contents of the building components into a limited, clearly defined taxonomic system; define relevant physical damage measures (DM) for each category; and create fragility functions for each damage state, p[DM|EDP]. Given this an p[EDP], we will elucidate and illustrate the calculation of p[DM]. Decision variables. These decision variables (DV) measure overall facility performance in terms most relevant to facility stakeholders. For the University of California, DV is most likely to include the probability of operational failure (parameterized as the event that restoration time exceed some threshold level), and may include the probability of life-threatening displacement of equipment and contents. We will elucidate and illustrate a methodology for calculating p[DV|DM] and, given p[DM], the calculation of p[DV]. Resources provided here. This reader can find here geotechnical studies, hazard information, and a combined report exercising the PEER methodology on the UC Science Building testbed.
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