Report - PEER - University of California, Berkeley

all of the nonstructural fragility functions required to simulate a building’sperformance. The project will rely on independent researchers and the suppliers ofnonstructural components for much of this data. An important task of the ATC-58project is the development of standard procedures for establishment of nonstructuralfragility parameters so that independent researchers and component suppliers candevelop this data. Figure 9 is a hypothetical fragility curve for a single drift-sensitivenonstructural component (exterior curtain walls) showing the probability of variousdamage states: cracking of panels, breakage of glass, fallout of glass, and failure ofpanel connections, as a function of interstory drift. The fragilities shown in the figureare illustrative only and are not representative of real data.Probabiltiy of Damage StateInitiation10.80.60.40.200 0.02 0.04 0.06 0.08 0.1Peak Interstory Drift RaioPanel CrackingGlass BreakingGlass FalloutConnection FailureFigure 7. Representative nonstructural fragility curve.Loss functions are used to estimate the probable value of the various losses,including repair costs, life loss and loss of use, given that the structure andnonstructural components and systems are damaged to different levels. Lossfunctions related to repair cost and restoration time can be developed by theorizingdifferent levels of damage to representative buildings and asking general contractorsand cost estimator to develop estimates of the cost and time to complete repair work.Estimation of losses and repair times associated with restoration of damaged facilitiestend to be highly uncertain and are dependent on such random factors as theefficiency of the contractor, the availability and pricing of labor and materials in thepost-earthquake environment, weather conditions, the occurrence of aftershocks, thetime necessary to effect designs for the repair, the specific repair methods developedby individual engineers, and whether or not the building will remain partiallyoccupied while repairs are implemented. Other uncertainties include the Owner’sefficiency in retaining design teams and contractors to perform the necessary work,the availability of insurance or other sources of funding for the repair work, and theoccupancy of the building and its tolerance to operations during repair work. Figure 8is a hypothetical loss function for the repair costs associated with damaged steelmoment connections. Similar loss functions will be developed for other types ofstructural and nonstructural damage and for restoration times.98