Shaking table experiments on soil isolation with using geosynthetics for medium rise buildings

In this study, the results of the preliminary study on a proposed soil isolation method by using geosynthetics for mitigating the seismic hazards of medium-rise buildings are presented. Geotechnical seismic isolation (GSI) system is comprised of a geotextile laid over a geomembrane located within a soil profile beneath the structure with a cylindrical shape. This system stands on the concept of the dissipation of the seismic energy via sliding. Geosynthetics placed within a soil profile can absorb seismic energy and transmit smaller ground motions to an overlying structure. To obtain the more reliable results and to observe soil-structure behavior during the earthquake excitations, an experimental setup was developed. The effectiveness of the proposed GSI system was assessed by comparing the response of performed shaking table experiments with and without GSI material. The comparative results of experiments revealed that GSI system can affect the horizontal accelerations, horizontal drifts, Arias intensity, base shear, and base moment of the building model. By using the proposed GSI isolation system, seismic energy transmitted from ground to structure is dissipated through slip displacement between geotextile and geomembrane. Noticeable improvements were obtained on the seismic performance of the building model against strong ground motion. More importantly, it is revealed that soil isolation with geosynthetics can be used to mitigate the earthquake hazards for medium-rise buildings in developing countries.