Metallic-grid and geofabric reinforcement of level ground as a liquefaction countermeasure

Abstract

Metallic-sheet and geofabric net inclusions are investigated as a liquefaction countermeasure in saturated loose cohesionless soil layers. Centrifuge model testing is employed to assess the beneficial effects of such inclusions. In this study, a brief literature review of current research is presented, and the results of 14 dynamic centrifuge tests on six different soil models are discussed The inclusions consist of either: i) metal sheet-grids placed at an angle of 45 degrees to the horizontal, or 2) geofabric-jute fiber placed in horizontal layers. Accelerometers, pore pressure and displacement transducers are used to monitor the soil system response to base dynamic excitation. Tests at different input motion amplitudes showed no detectable improvement in the soil resistance to liquefaction. Thus, it appears that such flexible inclusions have no significant impact on the soil system stiffness; and cause no reduction in the cyclic shear strains leading to liquefaction. Nevertheless, reduction in post liquefaction shear deformations might result in certain cases, and additional research is needed to clarify this issue. Based on the results of this experimental program, the potential for practical applications is discussed.