Numerical modelling methods for seismic soil-structure-interaction analysis

地震土-结构相互作用分析的数值模拟方法

• 批准号: 452612-2013
• 负责人: Kwon, OhSung
• 金额: $ 1.82万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Engage Grants Program
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=541008
• 关键词: Numerical; modelling; methods; seismic; soil

The research aims to understand the accuracy and limitations of commonly used numerical modelling methods for seismic soil-structure-interaction (SSI) analysis. To accurately simulate the seismic SSI effect, it is necessary to model various components such as seismic wave propagation from bedrock to surface through inelastic soil medium, inelastic behaviour at the soil-foundation interface (gap opening/closing, friction, soil yielding), dynamic response of the structure, and radiation of wave due to the dynamic response of the structure. Modelling all these components requires significant efforts and computing time. Thus, only a few attempts have been made so far in which the inelastic soil-structure system is modelled comprehensively. In the current seismic design and performance assessment practice, the seismic SSI is accounted for by using simplified modelling methods. For example, the effects of foundations are often approximately modelled using a secant stiffness at the maximum response of the foundation. In many research projects, the foundation is modelled by assigning nonlinear springs either as a single lumped spring or as Winkler-type springs. Sometimes lumped mass and damping elements are assigned in various configurations to simulate inertial interaction effect. The accuracy of these modelling methods in comparison with the comprehensive numerical modelling approach has not been clearly understood. The main scope of the proposed study is to understand the accuracy of different modelling methods such as 1) a comprehensive finite element (FE) model including inelastic wave propagation from bedrock to surface and nonlinear SSI effect, 2) an FE model in which the free field surface motion is applied as an effective force to a structure, and 3) a SSI model in which the effect of soil and foundation is considered using a nonlinear coupled macro element. The research results will provide confidence on the simplified modelling methods. Successful completion of the project will lead to implementation of the simplified modelling methods in the products of the industry partner.

该研究旨在了解地震土-结构相互作用（SSI）分析常用数值模拟方法的准确性和局限性。为了准确模拟地震 SSI 效应，需要对各种组件进行建模，例如地震波通过非弹性土壤介质从基岩到地表的传播、土壤-地基界面的非弹性行为（间隙张开/闭合、摩擦、土壤屈服）、动态结构的响应，以及由于结构的动态响应而产生的波辐射。对所有这些组件进行建模需要大量的工作和计算时间。因此，迄今为止，仅进行了一些对非弹性土-结构系统进行全面建模的尝试。在当前的抗震设计和性能评估实践中，地震SSI是通过使用简化建模方法来考虑的。例如，通常使用地基最大响应处的割线刚度对地基的影响进行近似建模。在许多研究项目中，基础是通过将非线性弹簧分配为单个集总弹簧或温克勒型弹簧来建模的。有时，集中质量和阻尼元件被分配在各种配置中以模拟惯性相互作用效应。与综合数值建模方法相比，这些建模方法的准确性尚不清楚。本研究的主要范围是了解不同建模方法的准确性，例如 1) 综合有限元 (FE) 模型，包括从基岩到地表的非弹性波传播和非线性 SSI 效应，2) 有限元模型，其中自由场表面运动作为有效力施加到结构上，3) SSI 模型，其中使用非线性耦合宏观单元考虑土壤和地基的影响。研究结果将为简化建模方法提供信心。该项目的成功完成将导致在行业合作伙伴的产品中实施简化的建模方法。