Report - PEER - University of California, Berkeley

where the PFHA is in g’s, DM is the damage measure in cm, and c 1, c ,2c are3constants depending upon the equipment category and the probability of exceedence.For example, for equipment with Category 1, the coefficients become, c 1= 0.35, c 2=0.0374 and c 3= -0.0017 for a 5% probability of exceedence. A family of curvessimilar to Figure 6, and summary statistics for use in Equation 10, for the categorieslisted in Table 1, and considering other damage measures are provided in RayChaudhuri and Hutchinson (2004b).5. CONCLUSIONSIn this paper, seismic fragility curves, associating the probability of exceedance of adefined limit state (a damage measure, DM) with an engineering demand parameter(EDP), are developed for a range of rigid, sliding-dominated science equipmentmounted on bench surfaces. For this study, only uniaxial seismic excitation isconsidered to provide insight into the contributions and sensitivity of the fragility todifferent uncertain parameters. Uncertain parameters considered in this study include:(i) static and kinetic coefficients of friction ( µ andsµ ) and (ii) supporting (benchkand building) characteristics. Fragility curves are developed for a stiff reinforcedconcrete (RC) building, and two flexible steel buildings (Steel-1 and Steel-2). Asimple approach for generalizing these curves is presented, which will be usefulwhere an unknown magnitude of DM is desired in seismic performance assessment.ACKNOWLEDGEMENTSSupport of this work was provided in part by the Earthquake Engineering ResearchCenters Program of the National Science Foundation, under Award Number EEC-9701568 through the Pacific Earthquake Engineering Research Center (PEER).Helpful comments and suggestions by Dr. Mary Comerio, Test Bed Manager; groundmotions provided Dr. Paul Sommerville and the RC building floor level time historiesprovided by Dr. Khalid Mosalam are greatly appreciated.REFERENCESChoi, D., and C. C. D. Tung. (2002). “Estimating sliding displacement of anunanchored body subjected to earthquake excitation.” Earthquake Spectra. 18(4):601–613.Garcia, L. D., and T. T. Soong. (2003). “Sliding fragility of block-type non-structuralcomponents. Part 1: Unrestrained components.” Earthquake Engineering andStructural Dynamics. 32: 111–129.Hutchinson, T. C., and S. Ray Chaudhuri. (2003). “Bench and shelf-mountedequipment and contents: shake table experiments.” In the Proceedings of theApplied Technology Council Seminar on Seismic Design, Performance, and207