Experimental investigation on flow deformation of liquefiable soil reinforced with geogrids

The main causes for damage of buildings during earthquake are large deformation and lateral displacement of the soil induced by liquefaction. Using the geogrids as the main reinforcement materials, a series of shaking table tests are conducted on the liquefiable soil under the load of buildings in order to study the effects of different reinforcement schemes on the flow deformation of the soil. Three different reinforcement schemes are considered, including horizontal layered geogrids, package of geogrids, geogrids together with non-woven fabrics. The dvelopment of excess pore water pressure, the settlement of buildings and the strain properties of geogrids are obtained from the shaking table tests. The results show that the liquefaction behaviors of foundation soil can not be changed by the geogrids since the peaks of excess pore water pressure are equal at the same depth, but the excess pore water pressure dissipates more quickly for the reinforcement scheme with geogrids + non-woven fabrics. Compared with that of the other two kinds of reinforcement schemes, the settlement of buildings of the reinforcement scheme with geogrids together with non-woven fabrics is the smallest, which decreases by 24% of the settlement without reinforcement. Besides, the strain crest at the central position of the geogrids is less than that at their edge position. Using the geogrids + non-woven fabrics reinforcement scheme, the non-woven fabrics has better restriction on the liquefiable soil in coverage area because of its large surface, which limits the vertical movement of sand particles. In addition, the force between sand particles and non-woven fabrics will transfer to the geogrids, which will be beneficial to the friction between soil and geogrids. Finally, the friction can further restrict the flow deformation of liquefiable soil.