Two SPTs and two CPTs for ground before and after stabilization, three static loading tests for the stabilized ground with stone columns were performed. It was found that stone columns strengthened the resistance to seismic liquefaction of a saturated clayey silt layer and increased the ground bearing capacity two times. From a water preloading test of an oil tank on the improved ground it was obtained that stone columns not only decreased the total and differential settlement of the tank but also speeded the consolidation rate of the ground. Stone columns also reduced the initial excess pore water pressures developed in the improved ground in comparison with those in the unimproved one
