群桩压入挤土效应的解析计算及试验对比

Analytical calculation and comparative test on compacting effects of jacked pile groups

采用孔扩张理论对静压桩挤土效应进行模拟计算,假定地基土符合修正剑桥模型,推导得出单桩压入过程中土体位移和孔隙水压力的解析表达式。以此为基础,通过叠加得到群桩压入过程中桩周土体挤土效应的理论解答。同时,在杭州地区进行了群桩静力压入的现场试验,发现桩周土体的水平位移随离排桩的距离呈指数衰减。解析计算值与试验结果较接近,证明了该模拟计算方法的有效性。

Both the excess pore press and soil displacement induced by single pile installation were obtained by taking the soil as modified Cambridge model.Accordingly,the theoretical formula was obtained on the compacting effects caused by the installa-tions of a group of this type piles.Meanwhile,some tests were conducted in Hangzhou,in which a trend of a logarithmic decay trend of horizontal soil displacement with the radial distance were observed.It is proved that this proposed theoretical method is feasible as the values calculated by the presented formula are consistent with the field test results.