Effects of separation distance and geometric misalignment on seismic pounding between base-isolated and fixed-base RC buildings
Archives of Civil and Mechanical Engineering, cilt.26, sa.5, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 26 Sayı: 5
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s43452-026-01615-1
- Dergi Adı: Archives of Civil and Mechanical Engineering
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Central & Eastern European Academic Source (CEEAS), Compendex, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO), Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest)
- Anahtar Kelimeler: Base isolation, Geometric misalignment, Near-field ground motion, Pounding, Separation distance
- Karadeniz Teknik Üniversitesi Adresli: Evet
Özet
Seismic pounding between adjacent structures is a significant concern in earthquake engineering, particularly in urban environments where insufficient separation distances are prevalent. This study investigates the effects of structural pounding on the seismic response of a base-isolated RC building placed next to a fixed-base structure, considering various pounding configurations and separation distances under near-field ground motions. The effects of geometric misalignment and insufficient seismic separation gaps are also evaluated in terms of selected structural response parameters and the seismic performance of adjacent buildings. To this aim, a four-story RC building was modelled with lead-rubber bearings (LRBs) as the base isolation system, while the adjacent structure was modelled as a conventional fixed-base building with similar geometric characteristics. Four different pounding configurations were defined based on the transverse offset between the buildings, representing common in-plan misalignments observed in real urban layouts. For each configuration, four levels of separation distances were introduced to assess the influence of clearance. The structural responses examined in the study include plastic hinge rotations of beams and columns, inter-story pounding forces, story accelerations, torsional moments, story rotations, and isolation story displacements. The results revealed that when sufficient separation distance (100% of the maximum isolator displacement) is provided, base isolation systems perform as intended, ensuring that structural elements predominantly remain within IO or LS limits. Conversely, inadequate separation distances (≤ 50%) lead to some exceedances of CP thresholds in the fixed-base system and, under certain eccentric pounding configurations, even in the isolated building. Furthermore, the results reveal that base isolation significantly enhances seismic reliability by limiting plastic hinge demands, reducing torsional moments, and controlling acceleration amplification; however, its effectiveness is drastically compromised when pounding restricts isolator displacements. It also underscores the need for explicit consideration of eccentric pounding configurations during the design and assessment of fixed base and base-isolated buildings.