Seepage Test on Liquefiable Sand

. This paper presents a series of seepage test on potentially liquefiable sand in the laboratory. Both downward and upward seepage direction were applied during the tests. These tests were conducted to investigate the influence of soil grain size and its distribution on hydraulic conductivity k, critical hydraulic gradient icr and piping failure mode of liquefiable sand. The seepage test results revealed that the hydraulic conductivity from upward seepage test is greater than the downward seepage test. The upward seepage test revealed that during liquefaction or piping failure/boiling, the hydraulic conductivity increased significantly, depending on the soil grain size, its ranging from 83 % to 321 %. The greater the size of soil grains the lesser potential of liquefaction or piping failure to occur. Because the pores space of the soil grain sufficient enough to dissipate the excess pore water pressure. The results and discussion in this study provide insightful information for the behavior of liquefiable sand when subjected to excess pore water pressure with different seepage force direction.