基于土塞效应的开口管桩挤土效应模拟计算

由于土塞效应的存在,开口预制桩的挤土效应不同于闭口桩,对其进行模拟计算具有现实的工程意义。将桩体的贯入过程模拟为一系列球孔的扩张,其中球孔的数量依据体积相等原则计算得出。模拟计算方法采用源汇法和源源法解答得出半无限体中一系列球孔扩张产生的应力场和位移场。同时,计算模型纳入了沉桩过程中桩侧摩阻力和土塞效应对解答的影响,并通过现场试验对模型计算的精确度进行评价。

SIMULATION COMPUTATION OF COMPACTION EFFECT FOR OPEN-ENDED PIPE PILE BASED ON PLUGGING EFFECT

The compaction effect for open-ended pipe pile is different to that for closed-ended pile due to the plugging effect. There are notable engineering significance and academic value in its simulation computation. A train of spherical cavities were adopted to simulate the pile installation process,and the quantity of spherical cavities would be obtained based on the principle of equivalent volume. The displacement and stress fields arised from spherical cavity expansion in semi-infinite by using source-source and source-image methods. Meanwhile,the influences of friction fatigue effect and soil plugging effect were included in the simulation computation. It is proved that this method is feasible through comparing the calculations with the field test results