Static Behaviors of Piles Foundation of High-Speed Railway Bridge

The vertical static load test is adopted to investigate 4 super-long bored piles in loess, in which the variation of the axis force in the piles is tested by the vibrating wire strain gauge. Hence, the bearing capacity behavior, load transfer mechanism, lateral friction and end bearing are researched in this paper. With the increase of the vertical static load, the results indicate that: (1) shaft force distribution of a bored pile is different from that of the original; this difference is mainly concentrated on the top 1/3 of the pile length; (2) the enhancing effect of static side resistance and the degradation effect of static side resistance are obtained in sandy soil; (3) the vertical static loading can induce a decrease in the axial stiffness of a single pile; and (4) axial stiffness of a single pile induces 40%∼70%.