Report - PEER - University of California, Berkeley

Table 2. Cases considered for this studyCASE Description1 Base case: brittle2 Base case: ductile3 Base case: brittle + low variability4 Base case: ductile + high variability5 CAR Ltd data for Izmit6 RMS Inc data for Izmit South EastTable 3. Values of parameters for Monte Carlo simulationCASE (see Table 2) 1 2 3 4 5 6β d for demand0.5 0.5 0.25 0.9 0.34 0.27spectrumβ c for capacity0.5 0.5 0.25 0.9 0.41 0.30(a u , d y , µ 1 , µ 2)Viscous damping ratio 7%κ, reduction factor on0.4hysteretic energya u (m/s 2 )3 3 3 3 2.5 2.4yield spectral accelnd y (m)0.11 0.11 0.11 0.11 0.11 0.1yield spectral disp.µ 1 (ductility to loss of 1.5 2.5 1.5 2.5 2.6 1.42strength)µ 2 (ductility to fracture) 3 4 3 4 5.2 3.5c (ratio of yield to 0.2 0.4 0.2 0.4 0.55 0.35residual strength)T (secs) - struct. period 1.2 1.2 1.2 1.2 1.32 1.28Table 4. Assumed relationship between deflection and damage stateDamage state Spectral deflection(mm)Approx equiv drift Assumed damageratioNone 0 - 38 0 – 0.5% 0%Low 38 – 68 0.5% - 0.9% 2%Moderate 68 – 126 0.9% - 1.7% 10%Extensive 126 – 330 1.7% - 4.5% 50%Complete >330 >4.5% 100%Figure 8a shows the predicted distributions for the ‘brittle’ and ‘ductile’ basecases; the ‘Type II’ distribution shape due to the brittle ‘cliff-edge’ changes to ‘Type405