Scholarlink

<p>This study develops a multi-layer seismic risk assessment framework integrating fragility analysis, demand sensitivity evaluation, global variance-based sensitivity, and dependence modelling to investigate fixed-base (FB) and base-isolated (BI) reinforced concrete frames subjected to far-field (FF) and near-fault (NF) ground motions. Incremental dynamic analysis (IDA) was performed using 44 records across four GM categories, generating fragility curves for interstorey drift (MIDR), roof drift (MRDR), base shear (MBS), top-floor acceleration (MTFA), and Maximum Isolator Displacement (MID). Results confirm that isolation effectively reduces drift and acceleration demands, achieving 30–65% reductions compared to FB systems; however, NF pulse-type excitations impose large isolator displacements, with BD often approaching or exceeding design capacity. Scenario- and interval-based sensitivity analyses further identified BD and shear as dominant near-fault demand drivers. Sobol and Morris indices revealed that drifts and shear are primarily governed by spectral velocity content (PGV/PGA), whereas accelerations remain controlled by PGA. Copula dependence models demonstrated that MRDR co-escalates with MIDR in FB frames, while MID drives the joint escalation of roof drift and shear in BI systems. Accordingly, the proposed framework provides an integrated basis for identifying governing fragility parameters and their interactions, offering actionable insight for performance-based seismic design in near-fault environments.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Comparative seismic assessment of base-isolated and fixed-base RC buildings: integrating fragility, sensitivity, and dependence under near- and far-fault motions

  • 期刊论文

  • 发表日期：

    2025年11月27日

查看全文
  • Amit Thoriya,
  • Husain Rangwala,
  • Tarak Vora,
  • Mazhar Dhankot

摘要

This study develops a multi-layer seismic risk assessment framework integrating fragility analysis, demand sensitivity evaluation, global variance-based sensitivity, and dependence modelling to investigate fixed-base (FB) and base-isolated (BI) reinforced concrete frames subjected to far-field (FF) and near-fault (NF) ground motions. Incremental dynamic analysis (IDA) was performed using 44 records across four GM categories, generating fragility curves for interstorey drift (MIDR), roof drift (MRDR), base shear (MBS), top-floor acceleration (MTFA), and Maximum Isolator Displacement (MID). Results confirm that isolation effectively reduces drift and acceleration demands, achieving 30–65% reductions compared to FB systems; however, NF pulse-type excitations impose large isolator displacements, with BD often approaching or exceeding design capacity. Scenario- and interval-based sensitivity analyses further identified BD and shear as dominant near-fault demand drivers. Sobol and Morris indices revealed that drifts and shear are primarily governed by spectral velocity content (PGV/PGA), whereas accelerations remain controlled by PGA. Copula dependence models demonstrated that MRDR co-escalates with MIDR in FB frames, while MID drives the joint escalation of roof drift and shear in BI systems. Accordingly, the proposed framework provides an integrated basis for identifying governing fragility parameters and their interactions, offering actionable insight for performance-based seismic design in near-fault environments.