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Report - PEER - University of California, Berkeley

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15 F (kN)Experimental1600DataExperimentalAnalyticalData1200ModelAnalyticalModel8000400-30 0 30u (mm) 00 510Cycle number-15Figure 7. Comparison <strong>of</strong> experimental data and analytical model for ES4.STRONG GROUND MOTIONSA set <strong>of</strong> 40 strong motion records are selected from 14 different earthquakes. Thedates and magnitudes <strong>of</strong> the earthquakes are Tokachi Oki 1968 (8.2), Chi-Chi 1999(7.6), Kocaeli 1999 (7.4), Miyagi Oki 1978(7.4), Kern County 1952 (7.4), Kobe 1995(6.9), Loma Prieta 1989 (6.9), Erzincan 1992 (6.9), Gazli 1976 (6.8), Spitak 1988(6.8), San Fernando 1971 (6.7), Imperial Valley 1979 (6.5), Irpinia 1980 (6.5) andWhittier Narrows 1987 (6.0).These 40 ground motion components are grouped with respect to the siteconditions as stiff (NEHRP B, C) and s<strong>of</strong>t (NEHRP D, E). There are 20 groundmotion components in each group. The mean elastic acceleration and displacementresponse spectra <strong>of</strong> each group are shown in Figures 8.a and 8.b, respectively, for 5%damping. It is observed that the intensity levels <strong>of</strong> the two groups are similar in shortand medium period ranges, however ground motions recorded on s<strong>of</strong>t soil sitesexhibit larger intensities than those on stiff sites at periods longer than 0.8 seconds.The results presented in the following section are arranged for considering theinfluence <strong>of</strong> site characteristics on inelastic displacements <strong>of</strong> deteriorating systems.1.0300.8Stiff Soil 25 St iff Soil20 S<strong>of</strong>t SoilSa (g)0.60.40.20.0(a)S<strong>of</strong>t Soil0 1 2 3Period (s)Figure 8. Mean elastic acceleration and displacement spectra for each group.Eh (kNmm)Sd (cm)151050(b)0 1 2 3Period (s)429

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