Performance of Buildings on Liquefiable Soils: Evaluation and Mitigation

可液化土壤上的建筑物性能：评估和缓解

• 批准号: 1362696
• 负责人: Shideh Dashti
• 金额: $ 35.35万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1362696&HistoricalAwards=false
• 关键词: Performance; Buildings; Liquefiable; Soils; Evaluation

The primary objective of this award is to study the seismic response of buildings on liquefiable ground, and the effectiveness of liquefaction mitigation strategies in the context of building performance. Earthquake-induced liquefaction can cause substantial damage to buildings and infrastructure systems. Successful mitigation of this risk requires a reliable assessment of the liquefaction hazard and its consequences. This study combines physical and numerical modeling in geotechnical and structural engineering. Centrifuge experiments will be conducted to simulate realistic loading conditions on scaled models. The data from these tests serve two purposes: first, to improve understanding of the interaction between the liquefiable soil, foundation, and superstructure; and second, to calibrate and validate numerical models that are used in engineering practice. This research sets the groundwork for a performance-based liquefaction mitigation design methodology, thereby contributing to the earthquake resilience of urban areas in the U.S. and internationally. Through collaboration with the Colorado Alliance for Graduate Education and the Professoriate, outstanding students from underrepresented groups in engineering will be recruited. The project will also launch a new collaboration between the University of Colorado and Cambridge University, England, which will enhance the scope of the investigation and create a coordinated international effort to reduce liquefaction risk. This study constitutes a fundamental evaluation of the seismic performance of shallow founded structures on softened ground and the effectiveness of remediation strategies. A primary goal is to evaluate the potential tradeoffs of liquefaction mitigation, which, on the one hand, reduce pore pressure generation and settlements but, on the other hand, increase ground shaking intensity, possibly resulting in structural nonlinearity and damage. To accomplish this goal, a series of centrifuge tests will be conducted to study the performance of inelastic, moment-resisting structures, with and without mitigation, on liquefiable sand. Numerical simulations of the experiments will assess and improve the capabilities of existing predictive tools in capturing soil-foundation-structure-interaction and the influence of the properties of soil, structure, ground motion, and mitigation technique on buildings engineering demand parameters. For the first time, building nonlinearities and damage potential will be considered in evaluating liquefaction hazard, consequences, and mitigation. The development of well-calibrated predictive tools will transform the ability of our profession to reliably evaluate building response on softened ground and will build a strong foundation for the eventual development of performance-based mitigation design methodologies. The team will organize web-based seminars examining liquefaction from soil, structural, and societal perspectives to share knowledge with engineers and researchers.

该奖项的主要目的是研究可液化地面上建筑物的地震反应，以及建筑物性能背景下液化缓解策略的有效性。地震引起的液化可对建筑物和基础设施系统造成重大损害。成功地减轻这种风险需要对液化危险及其后果进行可靠的评估。这项研究结合了岩土和结构工程中的物理和数值模拟。将在比例模型上进行模拟真实载荷条件的试验。这些测试的数据有两个目的：第一，提高对可液化土壤、地基和上部结构之间相互作用的理解;第二，校准和验证工程实践中使用的数值模型。这项研究为基于性能的液化缓解设计方法奠定了基础，从而为美国和国际城市地区的地震恢复力做出了贡献。通过与科罗拉多研究生教育联盟和教授的合作，将招募来自工程学代表性不足群体的优秀学生。该项目还将启动科罗拉多大学和英国剑桥大学之间的新合作，这将扩大调查范围，并建立一个协调的国际努力，以减少液化风险。本研究为软化地基上浅基础结构的抗震性能及补救措施的有效性提供了基本的评估依据。主要目标是评估液化缓解的潜在权衡，一方面，减少孔隙压力的产生和沉降，但另一方面，增加地面震动强度，可能导致结构非线性和损坏。为了实现这一目标，将进行一系列离心试验，研究非弹性抗弯结构的性能，减轻和不减轻，在可液化砂。实验的数值模拟将评估和提高现有预测工具在捕获土壤-基础-结构-相互作用以及土壤、结构、地面运动和缓解技术对建筑物工程需求参数的影响方面的能力。在评估液化危害、后果和缓解措施时，将首次考虑建筑物的非线性和破坏潜力。校准良好的预测工具的开发将改变我们的专业能力，可靠地评估建筑物对软化地面的反应，并将为基于性能的缓解设计方法的最终发展奠定坚实的基础。该团队将组织基于网络的研讨会，从土壤，结构和社会角度研究液化，与工程师和研究人员分享知识。