Evaluation of recovery of wall friction after penetration of skirts with laboratory and field tests

摘要

When skirt suction foundations are installed into cohesive soils, wall friction resistance on skirts reduces due to strength decrease of remolded soil along the skirts and the shear strength gradually recovers through dissipation of excess pore water pressure and thixotropy. Experiments in a laboratory and a field have been conducted to evaluate the recovery for alluvium soft clay in Osaka Bay, Japan. Laboratory tests under 1 g and 25 g fields demonstrate that the pore water pressure dissipation has smaller effect on the recovery of wall friction than thixotropy for the clay. The result of the field tests using a larger scale skirt corresponds with that of the laboratory tests and nearly the same recovery rate of the wall friction is obtained.