Development of a macro element for seismic SSI Analysis of shallow foundations

浅基础地震 SSI 分析宏单元的开发

• 批准号: 469055-2014
• 负责人: Kwon, OhSung
• 金额: $ 1.4万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=563236
• 关键词: Development; macro; element; seismic; SSI

The objective of the proposed research is to develop a macro element for a soil-shallow foundation system that can take into account the inelastic behaviour of near-field soil as well as the frequency-dependent dynamic impedance of far-field soil. The element will greatly simplify the modelling method for a soil-shallow foundation system and will increase the accuracy of the evaluation of structural responses under earthquake excitation. It has been well acknowledged that the soil-structure interaction (SSI) influences the response of a structure that is subjected to earthquake excitation, but the consideration of SSI is not straightforward due to the complexities in the dynamic behaviour of soil-foundation systems. In the proposed research, an element will be developed that can capture the inelastic behaviour of near-field soil as well as the frequency-dependent dynamic of far-field soil. The development will be based on the integration of gyromass-spring-damper assemblies and a plasticity-based macro element. The inelastic macro element can take into account the interaction of multi-axial loads (axial force, shear force, and moment). The gyromass-spring-damper assemblies can capture the frequency-dependent dynamic response of far-field soil. Integrating these two elements and calibrating model parameters for typical soil types and foundation configurations will lead to a computationally efficient yet sufficiently accurate model for shallow foundations. The proposed main research tasks are 1) integration of two modelling approaches for near- and far-field soil, 2) calibrating lumped model parameters for inelastic macro spring element against a sophisticated finite-element model, 3) verifying the developed model against finite element analyses, and 4) applying the element to a typical low-rise building structure and a bridge structure. The use of the computationally efficient yet accurate numerical element will allow engineers to develop an optimized design for a structural system and accurately evaluate the performance of a structure in the event of an earthquake, which will lead to a resilient society against seismic hazard.

提出的研究目标是为土-浅基础系统开发一个宏观单元，该单元可以考虑近场土壤的非弹性行为以及远场土壤的频率相关动力阻抗。该单元将大大简化土-浅基础系统的建模方法，提高结构在地震作用下的响应评估的准确性。众所周知，土-结构相互作用（SSI）会影响结构在地震激励下的响应，但由于地基系统动力特性的复杂性，考虑SSI并不简单。在提出的研究中，将开发一种元素，可以捕捉近场土壤的非弹性行为以及远场土壤的频率相关动态。该发展将基于陀螺仪质量-弹簧-阻尼器组件的集成和基于塑性的宏观元素。非弹性宏观单元可以考虑多轴载荷（轴力、剪力和弯矩）的相互作用。陀螺质量-弹簧-阻尼器组合可以捕获远场土壤的频率相关动力响应。将这两个要素结合起来，并对典型土壤类型和基础配置的模型参数进行校正，将得到一个计算效率高且足够精确的浅基础模型。提出的主要研究任务是：1)整合近场和远场土壤的两种建模方法；2)根据复杂的有限元模型校准非弹性宏观弹簧单元的集总模型参数；3)通过有限元分析验证所开发的模型；4)将该单元应用于典型的低层建筑结构和桥梁结构。使用计算效率高且精确的数值元素将允许工程师开发结构系统的优化设计，并在地震发生时准确评估结构的性能，这将导致一个抵御地震危害的弹性社会。