Abstract: The application of rigid-drainage pile, combining vertical drainage and rigid pile, is a new technology for mitigation of liquefaction. Shaking table tests were carried out to investigate the performance of the rigid-drainage pile against liquefaction. The response of excess pore water pressure, acceleration and lateral displacement of pile top were monitored and analyzed. The results indicated that the use of rigid-drainage pile was an effective method to mitigation of liquefaction. There was much water drainage from the drainage pile when the shaking motion was applied, yet no water drainage for the ordinary pile. The mean value of peaks of excess pore water pressure decreased 12% for the rigid-drainage pile comparing to the ordinary pile. The value of excess pore water pressure approximately decreased 13% when the excess pore water pressure became stability. The effect of drainage was mainly in the previous period of shaking. The lateral permanent displacement on pile top decreased 27% for rigid-drainage pile compared with ordinary pile. The liquefaction, shear-strain hysteresis loops at previous stage were more pronounced than that of post liquefaction stage. the secant modulus of rigid-drainage pile is larger than the ordinary pile. The results of the tests illustrated the effectiveness of rigid-drainage pile in mitigation of liquefaction.

Key words: rigid-drainage pile, shaking table test, pile groups, excess pore water pressure, lateral permanent displacement