AN EVALUATION OF EFFECT ON LIQUEFACTION MITIGATION AND EARTH PRESSURE ON WALLS FOR LATTICE SHAPED GROUND IMPROVEMENT USING CENTRIFUGE MODELLING TESTS

Abstract

  A lattice-shaped ground improvement with a deep mixing soil stabilization is one of the liquefaction mitigation techniques, which prevents sandy soil from liquefaction by constraining its shear deformation. For the design method against level-2 earthquakes, it is very effective to adopt a concept of performance-based design and to assure the external stability of structures allowing a failure of improved walls. Then, aiming at introducing performance-based design concept into the design method, we conducted centrifuge modeling tests and examined the effect on liquefaction mitigation and the earth pressures on improved walls that are important factors for the design. As a result, the authors can see as follows: a potential of liquefaction increases with a decrease in the grid space, the accelerations of improved walls are predominant on the dynamic earth pressures, and the amplitude of dynamic earth pressures sharply rises and the distribution in the vertical direction is clearly changed while the inner sandy soil reaches to liquefaction.