Shaking table tests on liquefaction resistance performance of single rigid-drainage pile

The rigid-drainage pile is a new type of pile which combines vertical drainage and rigid pile. To investigate the liquefaction resistance, the drainage, response of excess pore water pressure, acceleration and lateral permanent displacement of pile head under upper loads are measured based on shaking table tests. The results are compared with those of ordinary pile tests. It is indicated that the rigid-drainage pile is an effective approach for mitigation of liquefaction. The phenomenon of sand boil is restrained effectively in the range of one time the pile diameter, while sand boil occurs significantly in ordinary pile tests. The peak of excess pore water pressure ratio of rigid-drainage pile tests is 50% of that of ordinary pile ones at a distance of 0.5 time the pile diameter, and the rigid-drainage pile can dissipate the excess pore water pressure more rapidly. It takes 6 s for the peak of excess pore water pressure ratios to decrease to 0.7 in the rigid-drainage pile tests, and in the ordinary pile tests it is 17 s. The peak of acceleration is 0.2g at a distance of 0.5 time the pile diameter, and it is only 0.09g in the ordinary pile tests at the same monitor point, which means that the peak of acceleration in ordinary pile tests is decreased by 100% approximately compared to that of rigid-drainage pile. With the continuation of loading process, the amplitude vibration of rigid-drainage pile head is tiny, and it only occurs in the initial moments (3 s). The peak lateral permanent displacement is 0.6 cm in the ordinary pile tests and the amplitude vibration continues to the end of shaking. The peak lateral permanent displacement is around