Abstract The seismic response of structures is very complex owing to the behaviour of soils during an earthquake. Traditional seismic designs rely on the assumption that the base of the foundation is fixed. However, the foundation tends to displace owing to the flexible nature of the soil. Indian seismic code and other codes though incorporate the effect of soil-structure-interaction (SSI), but in a very broad sense, and thus are inadequate. This study aims to understand the seismic performance of reinforced concrete (RC) framed buildings designed according to the Indian code, considering soil flexibility. The seismic vulnerability of buildings is investigated through pushover and fragility analysis. Six RC framed buildings with different heights, encompassing low-, mid- and high-rise buildings, covering a wide range of lateral periods (short-, medium- and long-periods), are considered. These buildings are considered to be resting on raft foundations. The soil flexibility for four types of soft clay soil is computed based on shear velocity, shear modulus and density. A variational study for a range of soft soils in combination with short-, medium- and long-period structures is carried out. Fragility curves and damage probability matrices are developed using push over analysis incorporating SSI. The overall conclusions from the fragility curves are that the soil flexibility may significantly increase the seismic vulnerability of low-rise RC framed buildings, and the performance of high-rise buildings may be improved by taking this into consideration.

中文翻译：

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土壤柔韧性对规范设计的钢筋混凝土框架建筑抗震脆性的影响

摘要 由于地震期间土体的行为，结构的地震反应是非常复杂的。传统的抗震设计依赖于地基基础是固定的假设。然而，由于土壤的柔韧性，地基往往会发生位移。印度地震规范和其他规范虽然包含了土壤结构相互作用（SSI）的影响，但在非常广泛的意义上，因此是不够的。本研究旨在了解根据印度规范设计的钢筋混凝土 (RC) 框架建筑物的抗震性能，同时考虑土壤柔韧性。通过 Pushover 和脆性分析研究建筑物的地震脆弱性。六座不同高度的钢筋混凝土框架建筑，涵盖低、中、高层建筑，涵盖了广泛的横向时期（短、中期和长期），被考虑。这些建筑物被认为是建立在筏形基础上。根据剪切速度、剪切模量和密度计算四种软粘土的土壤柔韧性。对一系列软土结合短周期、中周期和长周期结构进行了变分研究。脆性曲线和损坏概率矩阵是使用包含 SSI 的推压分析开发的。脆性曲线的总体结论是，土壤柔韧性可能会显着增加低层钢筋混凝土框架建筑的抗震脆弱性，考虑到这一点，高层建筑的性能可能会得到改善。根据剪切速度、剪切模量和密度计算四种软粘土的土壤柔韧性。对一系列软土结合短周期、中周期和长周期结构进行了变分研究。脆性曲线和损坏概率矩阵是使用包含 SSI 的推压分析开发的。脆性曲线的总体结论是，土壤柔韧性可能会显着增加低层钢筋混凝土框架建筑的抗震脆弱性，考虑到这一点，高层建筑的性能可能会得到改善。根据剪切速度、剪切模量和密度计算四种软粘土的土壤柔韧性。对一系列软土结合短周期、中周期和长周期结构进行了变分研究。脆性曲线和损坏概率矩阵是使用包含 SSI 的推压分析开发的。脆性曲线的总体结论是，土壤柔韧性可能会显着增加低层钢筋混凝土框架建筑的抗震脆弱性，考虑到这一点，高层建筑的性能可能会得到改善。脆性曲线和损坏概率矩阵是使用包含 SSI 的推压分析开发的。脆性曲线的总体结论是，土壤柔韧性可能会显着增加低层钢筋混凝土框架建筑的抗震脆弱性，考虑到这一点，高层建筑的性能可能会得到改善。脆性曲线和损坏概率矩阵是使用包含 SSI 的推压分析开发的。脆性曲线的总体结论是，土壤柔韧性可能会显着增加低层钢筋混凝土框架建筑的抗震脆弱性，考虑到这一点，高层建筑的性能可能会得到改善。