Abstract: Considering the stress history and initial stress anisotropy of natural saturated clay under K0-consolidated condition, a theoretical solution to the jacking force of pile was derived by modeling the pile shaft penetration process as the spherical and cylindrical cavity expansions, respectively. Then, based on the radial excess pore water dissipation after the pile installation, an analytical solution to the time-dependent bearing capacity of the jacked pile was derived by considering the relaxation effect of the soil around the pile during reconsolidation process. And the theoretical expression for the timeliness coefficient of jacked pile bearing capacity in K0-consolidated natural saturated clay was established. The validity of the present solution was verified by the centrifuge model test and field test respectively, and the time-dependent bearing capacity were discussed in detail. The results show that, the time-dependent bearing capacity within a short time after pile installation can be attributed to the combination of the excess pore water pressure dissipation and the thixotropy recovery of the surrounding soils. After a certain rest time, the dissipation of the excess pore water pressure is the main reason for the increase of the bearing capacity.

Key words: terminative jacking force, time-dependent bearing capacity, centrifuge test, timeliness coefficient ratio