ABSTRACT

This paper presents an insight on the seismic response and seismic risk of base-isolated structures performed within the RINTC project, considering different configurations of rubber-based isolation systems. This represents an in-depth revision of past works due to the adoption of more robust and accurate isolator model. Four archetype 6-storeys RC frame buildings are examined, representing both new designed isolated buildings and existing buildings retrofitted with seismic isolation, differing in age of construction and location (the cities of L’Aquila (central Italy) and Naples (southern Italy)). All the isolation systems are designed in accordance with the current Italian Seismic Code. Seismic performance assessment is performed by multi-stripe nonlinear time history analysis. The annual failure rates for two different performance levels, namely Global Collapse and Usability Preventing Damage, are computed. The results point out that all isolation systems work effectively in limiting damage while they show a quite low margin with respect to collapse, regardless of the dominant failure mode, which is governed by the more fragile component among isolation system and superstructure. The annual failure rates derived for base-isolated buildings are critically reviewed and then compared with those obtained for similar new designed fixed-base RC buildings.

摘要

本文介绍了在 RINTC 项目中执行的基础隔震结构的地震响应和地震风险的见解，考虑了橡胶隔震系统的不同配置。由于采用了更强大和更准确的隔离器模型，这代表了对过去工作的深入修订。研究了四栋原型 6 层 RC 框架建筑，代表新设计的隔离建筑和经过隔震改造的现有建筑，建筑年龄和位置不同（拉奎拉市（意大利中部）和那不勒斯（意大利南部）） . 所有的隔离系统都是按照现行的意大利地震规范设计的。抗震性能评估通过多条非线性时程分析进行。两种不同性能水平的年故障率，即全局崩溃和可用性预防损坏，计算。结果表明，所有隔离系统都有效地限制了损坏，但它们在坍塌方面表现出相当低的裕度，而不管主要失效模式是由隔离系统和上层建筑中更脆弱的组件控制的。对基础隔离建筑物得出的年度故障率进行了严格审查，然后与类似的新设计的固定基础钢筋混凝土建筑物的年度故障率进行比较。这是由隔离系统和上层建筑中更脆弱的组件控制的。对基础隔离建筑物得出的年度故障率进行了严格审查，然后与类似的新设计的固定基础钢筋混凝土建筑物的年度故障率进行比较。这是由隔离系统和上层建筑中更脆弱的组件控制的。对基础隔离建筑物得出的年度故障率进行了严格审查，然后与类似的新设计的固定基础钢筋混凝土建筑物的年度故障率进行比较。