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.
