Table 1 Damage state limits for bridge piers and bearing systems (Choi et al. 2004; Karim and Yamazaki 2001; Hwang et al. 2001; Parghi and Alam 2017; Basnet and Suwal 2019)
Bridge Components | Damage Index | Slight (DS = 1) | Moderate (DS = 2) | Extensive (DS = 3) | Collapse (DS = 4) | |
|---|---|---|---|---|---|---|
Columns | A | Physical phenomenon | Cracking and spalling | Moderate cracking and spalling | Degradation without collapse failure | Failure leading to collapse |
B | Element ductility µκ | 2 > µκ > 1 | 4 > µκ > 2 | 7 > µκ > 4 | µκ > 7 (Choi et al. 2004) | |
C | Displacement ductility µd cracking | µd > µ first-yield (1.0) | µd > µ first-yield (1.20) | µd > µ first-yield (1.76) | µd > µ first-yield (4.76) (Hwang et al. 2001) | |
D | γ = (µd + βµh)/µu | 0.40 > γ > 0.14 | 0.60 > γ > 0.40 | 1.0 > γ > 0.60 | γ > 1.0 (Karim and Yamazaki 2001) | |
E | Load carrying capacity loss βh, βv | βh > 0% βv > 5% | βh > 2% βv > 10% | βh > 5% βv > 25% | βh > 20% βv > 50% (Basnet and Suwal 2019) | |
Bearing Systems | F | Drift ratio θ | θ > 0.007 0.2%–0.5% | θ > 0.015 0.5%–1.5% | θ > 0.025 1.5%–2.5% | θ > 0.050 > 2.5% (Parghi and Alam 2017) |
G | Displacement δ | δ > 0 mm | δ > 50 mm | δ > 10 0 mm | δ > 150 mm (Choi et al. 2004) |