Performance of Buildings on Liquefiable Soils: Evaluation and Mitigation

该奖项的主要目标是研究可液化地面上建筑物的地震反应，以及在建筑物性能方面缓解液化策略的有效性。地震引起的液化会对建筑物和基础设施系统造成严重破坏。成功地减轻这种风险需要对液化危害及其后果进行可靠的评估。本研究结合岩土工程和结构工程的物理和数值模拟。离心机实验将进行模拟真实的加载条件下的比例模型。来自这些试验的数据有两个目的：第一，提高对可液化土、基础和上部结构之间相互作用的理解；第二，校正和验证工程实践中使用的数值模型。本研究为基于性能的液化缓解设计方法奠定了基础，从而有助于美国和国际上城市地区的地震恢复能力。通过与科罗拉多研究生教育联盟和教授的合作，将招募来自工程领域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（University of Colorado）和英国剑桥大学（Cambridge University）之间的一项新的合作，这将扩大调查的范围，并建立一个协调一致的国际努力，以减少液化风险。本研究是对软弱地基上浅基础结构抗震性能和修复策略有效性的基础性评价。主要目标是评估缓解液化的潜在权衡，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破坏。为了实现这一目标，将进行一系列离心机试验，研究非弹性、抗弯矩结构在液化砂上的性能，有和没有减缓。实验的数值模拟将评估和改进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，将首次考虑建筑非线性和潜在损害。校准良好的预测工具的开发将改变我们的专业人员可靠地评估软化地基上建筑物反应的能力，并将为最终开发基于性能的缓解设计方法奠定坚实的基础。该小组将组织基于网络的研讨会，从土壤、结构和社会的角度研究液化，与工程师和研究人员分享知识。

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.