Geosynthetics for Foundation and Soil Isolation in Earthquake Hazard Mitigation

摘要：U东北的CMS-9634747在动力激励下，沿光滑的土工合成界面发生滑移变形，从而减少了通过界面传递的能量。因此，放置在已建设施基础下的土工合成衬垫可以吸收地震能量，从而将较小的地面运动传递到上面的结构。这种使用土工合成材料进行基础隔震的概念类似于结构工程中使用的机械隔震器。此外，在新的斜坡、路堤或水力填土内使用不同深度的土工合成衬垫--已知极易发生液化--可以减少土壤对地面运动的放大效应，并降低松散填土的液化潜力。这个概念被称为土壤隔离。这项研究计划通过实验和分析工作，调查使用土工合成材料作为基础和土壤隔离以减轻地震危险的技术可行性、实用性和局限性。这项研究的范围包括土工合成材料的振动台试验，这些试验表明土工合成材料在基础和土壤隔离方面具有最佳的前景。试验结果被用来建立和验证描述土工合成材料界面动力响应的本构模型。利用振动台对建筑物、挡水结构和土体剖面进行了模型试验，并将试验结果用于制定使用土工合成衬垫隔震的结构和土体剖面的动力响应分析程序。结果被用来确定需要进一步调查的领域，这将有助于将研究成果转化为工程实践。使用土工合成材料降低地震地面运动强度和降低液化潜力的创新概念可以极具成本效益，是传统地震灾害缓解措施的一种更简单的替代方案。

ABSTRACT: CMS-9634747, Mishac Yegian, Northeastern U Under dynamic excitation, slip deformations occur along a smooth geosynthetic interface, thus reducing the energy transmitted through the interface. As a result, geosynthetic liners placed under the foundation of a constructed facility can absorb seismic energy, and hence transmit smaller ground motions to the overlying structure. This concept of using geosynthetics for Foundation Isolation is similar to mechanical isolators used in structural engineering. In addition, using geosynthetic liners at different depths within new slopes, embankments or hydraulic fills -- known to be extremely vulnerable to liquefaction -- can reduce the soil amplification effect on the ground motion, and the liquefaction potential of loose fills. This concept is referred to as Soil Isolation. This research program investigates, through experimental and analytical work, the technical feasibility, practicality, and limitations of using geosynthetics for foundation and soil isolation to mitigate earthquake hazard. The scope of this research includes shaking table tests on geosynthetics that show the best promise for foundation and soil isolation. The experimental results are used to develop and validate constitutive models that describe the dynamic response of geosynthetic interfaces. Model tests on buildings, fluid retaining structures and soil profiles are conducted using a shaking table, and the results used to develop procedures for the analysis of the dynamic response of structures and soil profiles that are isolated using geosynthetic liners. The results are used to identify areas of need for further investigation that will help to transfer the research results to engineering practice. The innovative concept of using geosynthetics to reduce earthquake ground motion intensity, and to reduce liquefaction potential, can be extremely cost effective and a simpler alternative to conventional earthquake hazard mitigation me asures.