Comparison of seismic fragility of special moment frames in recent editions of ASCE 7 and ACI 318 regulations

The seismic safety levels provided by the three most recent editions of ACI and ASCE regulations for new moment frame structures are determined. Five special RC frames having 3, 5, 10, 15, 20 stories designed separately based on 318-99, 318-05, 318-11, associated UBC 97, 7-05, 7-10. A suit 10 consistent earthquake records is selected non-linear dynamic analysis buildings. Incremental conducted, corresponding fragility curves calculated. comparison results shows that buildings has considerably improved from 318-99 to 97 7-10, owing its larger part improvements made in two latter versions mentioned building codes. However, enhancement not uniform much less with fundamental periods, especially periods than 1.0 sec. For smaller 1 sec, collapse ratio increased up more 70%. increase 20%. Changes ASCE7 regard R-factor coefficients load combination equations introduction stricter requirements allowable story drift pinpointed be important factors. codes, regarding confinement plastic hinges configuration longitudinal reinforcement recognized influential changes.