Prediction method for time-dependent load-settlement relationship of a jacked pile

Considering the in-situ properties of the natural saturated clay strata, the pile installation effects are studied by the cavity expansion model. Based on Terzaghi’s one dimensional radial consolidation theory, the analytical solutions are derived for the time-dependent strength and shear modulus of the soil adjacent to a jacked pile. Then, based on the shear deformation performance of the surrounding soil during pile loading, the time-dependent load transfer models for pile shaft and pile base are established through the exponential function type load transfer curve, respectively, and a theoretical method is proposed for predicting the time-dependent load-settlement curve of a jacked pile in saturated clay strata. The proposed theoretical method is verified by the field tests. The time-dependent load-settlement performance and load transfer properties of the jacked pile after pile installation are studied. The results show that the evolution of the bearing performance of the jacked pile after pile installation is primarily because of the increase in the bearing performance of pile shaft. There are some discrepancies between the actual load-settlement performance of the jacked pile and the static loading test results after specific rest time. Thus, in actual engineering, the time-dependent bearing performance of jacked piles should be evaluated through the static loading tests with the aid of considering the evolution of the mechanical properties of the surrounding soil of piles.