Innovative Geotechnical Solutions for Base Isolation of Buildings

In the present study, a geotechnical seismic isolation (GSI) bed, composed of geosynthetic-reinforced sand-rubber tire shred mixture layer between the base of the building foundation and the supporting soil medium, is considered to mitigate ground vibrations. The index and engineering properties including dynamic properties of sand-rubber tire shred mixtures are carried out to assess their suitability for seismic base isolation of buildings. In addition to that, the liquefaction resistance of sand rubber mixtures is also evaluated. Further, laboratory-based model experiments and Finite Element (FE) modeling was carried out for footing resting on geogrid-reinforced GSI layer under static loading. Further, 2D seismic response of a typical building on GSI was also carried out using finite element code ABAQUS. Finally, results of a series of field experiments conducted to study the response of model footing resting on the geogrid-reinforced GSI bed subjected to horizontal ground vibration are presented. Further, a 3D finite element (FE) model of the field study was developed in the time-domain to simulate and investigate the response of geogrid-reinforced GSI bed on a multi-layered soil system for different surface wave characteristics. In general, it was found that GSI with geogrid reinforcement is found to be effective in the mitigation of ground vibrations due to earthquakes and other source of vibration.