Fundamental research on the dynamic behaviour of soils and the seismic stability of earth structures.

土动力行为及土结构地震稳定性基础研究。

• 批准号: 418383-2012
• 负责人: James, Michael
• 金额: $ 1.18万
• 依托单位: École Polytechnique de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=636099
• 关键词: Fundamental; research; dynamic; behaviour; soils

This research addresses two related topics; (A) the fundamental aspects of the dynamic behaviour of soil and (B) the seismic stability of earth structures. Topic A : Despite extensive research, there are aspects of each of these topics where there exist considerable uncertainty and further research is necessary to increase our understanding with the objective of improving evaluation procedures and thereby advancing the state of the practice.Natural soils and hydraulically deposited fills (e.g. tailings) are often characterized by layering of finer and coarser material (silt and sand). Instrumented seismic table testing will be used to characterize the dynamic response of such deposits and provide recommendations for their evaluation in engineering practice. Due to conflicting research on the effect of confining stress on liquefaction, the effect of confining pressure on normally and over-consolidated hydraulically-deposited soils will be evaluated using cyclic triaxial testing. This research may lead to revised correction factors for the evaluation of liquefaction in such soils.Topic B: Due to advances in the state of the practice and regulations, numerical analysis is increasingly to evaluate the seismic stability of earth structures. The utility of these analyses are restricted by the limitations of the constitutive models used to simulate material behaviour. A constitutive model that incorporates critical aspects of dynamic behaviour will be developed and implemented. The model will be based on correlations with widely used laboratory and in situ testing procedures and will consider: a hyperbolic stress-strain relationship, the effects of fines content, initial static shear and degree of consolidation, and post-liquefaction strength loss.Numerical and analytical methods will be compared to validate the use of the pseudo-static method and the Newmark displacement method for earth structures composed of materials subject to strength loss and liquefaction. Basic guidelines for dynamic numerical analysis will be developed.

这项研究涉及两个相关的主题：（A）土壤的动态行为的基本方面和（B）地球结构的地震稳定性。主题A：尽管进行了广泛的研究，但每个主题的某些方面都存在相当大的不确定性，有必要进行进一步的研究，以提高我们的理解，从而改进评估程序，从而推进实践的状态。天然土壤和水力沉积填料（例如尾矿）通常具有较细和较粗材料（粉土和砂）分层的特征。将使用仪器化地震台试验来描述这种沉积物的动态响应，并为工程实践中的评估提供建议。由于围压对液化影响的研究存在矛盾，因此将采用循环三轴试验评估围压对正常和超固结水力沉积土的影响。这项研究可能会导致修订的校正系数的液化评价在这样的so.Topic B：由于在实践和法规的国家的进步，数值分析越来越多地评估地震稳定性的地球结构。这些分析的效用受到用于模拟材料行为的本构模型的局限性的限制。一个本构模型，包括动态行为的关键方面将开发和实施。该模型将基于与广泛使用的实验室和现场测试程序的相关性，并将考虑：双曲线应力-应变关系，细粒含量，初始静剪和固结度的影响，和液化后强度损失。数值和分析方法将进行比较，以验证使用的伪-静力法和纽马克位移法，适用于强度损失和液化材料组成的土结构。将制定动态数值分析的基本准则。