Shaking table tests on shallow foundations over geocomposite and geogrid-reinforced liquefiable soils

Abstract

The present study presents the results of a series of 1 g shaking table tests modeling a 4 story building foundation overlying liquefiable soil reinforced by two different types of geosynthetics as liquefaction mitigation countermeasures. Models of geosynthetics including geogrid and geocomposite were used as reinforcement elements. Failure mechanisms; foundation and geosynthetic settlement; and pore water pressure built-up trends were considered as the indicators of geosynthetics performances. The failure mechanism was observed through a digital camera and analyzed based on a mesh of colored sand. The obtained results indicated the negligible effect of geogrids on the reduction of settlement as the failure mode was controlled by the pore water pressure and it was not influenced by geogrids. However, based on the experimental results the effectiveness of geocomposits in reducing the settlement due to impervious characteristics was evident. In addition, the a remarkable mitigation occurred in the case of settlement of soils between two geocomposite sheets, but the general performance of geocomposites was not satisfactory at all.