Seismic Performance Evaluation of Mid-Rise Concrete Buildings Equipped with Lead Rubber Bearings Using Fragility Curves

This study evaluates the seismic performance of mid-rise concrete moment-resisting frames (MRFs) equipped with lead rubber bearings (LRBs) using fragility curves. Two concrete buildings (۸- and ۱۲-story) were designed with and without LRBs in SAP software. Critical sections and stress ratios of structural members were extracted, and a representative ۲D frame was modeled in OpenSees. Incremental Dynamic Analysis (IDA) was performed using ۱۰ ground motion records, and fragility curves were derived based on inter-story drift ratios. Key findings include:• The LRB system significantly increased the structural period, with amplification factors of ۲.۲۲ and ۲.۱۷ for the ۸- and ۱۲-story buildings, respectively.• LRBs reduced inter-story drift by ۱۴.۳% (۸-story) and ۱۸.۵% (۱۲-story), enhancing seismic stability.• Structures with LRBs tolerated higher peak ground acceleration (PGA) before reaching failure thresholds.• The probability of earthquake-induced damage decreased by ۱۱.۸% (۸-story) and ۲۵.۷۵% (۱۲-story), indicating superior LRB effectiveness in taller buildings.These results highlight LRBs’ potential to mitigate seismic risk in mid-rise concrete structures, particularly in high-rise configurations.

کلیدواژه ها:

Mid-rise concrete buildings ، Lead Rubber Bearings (LRB) ، Incremental dynamic analysis (IDA) ، Fragility curves ، Structural period