在饱和软粘土中打桩,由于桩对土的挤压作用,桩周围土中会产生很高的孔隙水压力。这些超孔隙水压力随着桩入土时间的增加而逐渐消散,桩间土中的有效应力也相应增加,土的密度和强度随之增高。这就是所谓打桩后期的再固结作用。这一现象将导致桩侧摩擦力随时间增长而增长。所以单桩承载力并不是一个常数,而是随着时间在变化的。这一现象在工 In piles of saturated soft clay, due to the effect of piles on the soil, high pore water pressures are generated in the soil around the piles. These excess pore water pressures gradually dissipate as the pile’s time to soil increases, and the effective stress in the soil between the piles also increases, which increases the density and strength of the soil. This is the so-called reconsolidation of the post-piling period. This phenomenon will cause the pile side friction to increase with time. So the bearing capacity of a single pile is not a constant, but changes with time. This phenomenon is at work