有孔管桩群桩沉桩引起的超孔隙水压力模型试验分析

Model Experimental Analysis on Excess Pore Water Pressure due to Sinking of Pipe-pile Group with Holes

为了深入研究有孔管桩群桩沉桩引起的超孔隙水压力变化规律,基于室内模型试验,对无孔管桩群桩和3种布孔方式的有孔管桩群桩沉桩时引起的超孔隙水压力进行了监测,分析了沉桩顺序、布孔方式等因素对超孔隙水压力时空消散的影响,获得了无孔管桩群桩和3种布孔方式的有孔管桩群桩沉桩时超孔隙水压力随时间、深度、径向距离和沉桩顺序的变化规律。通过对比分析可知,有孔管桩群桩沉桩产生的超孔隙水压力小于无孔管桩群桩,表明有孔管桩群桩在一定程度上能降低超孔隙水压力,其中星状布孔方式的有孔管桩群桩沉桩产生的超孔隙水压力峰值最小,消散速率最快,最有利于减小沉桩挤土效应,沉桩效应最佳。

For the sake of researching the change law of excess pore water pressure during sinking of pipe-pile group with holes,based on indoor model test,the excess pore water pressures of pipe-pile without hole and 3kinds of pipe-pile group with holes caused by pile sinking are monitored.The influences of pile-sinking sequence and hole-disposal mode on the time-space dissipation of excess pore water pressure are analyzed.The variation rules of the excess pore water pressure of pipe-pile without hole and 3 kinds of pipe-pile group with holes dissipation with time,depth,radial distance and pile-sinking sequence during the process of pilesinking are obtained.Through the comparison and analysis,it is found that the excess pore water pressure of pipe-pile group with holes is less than that of the pile-pile group without hole,indicating that the pipe-pile group with holes can reduce excess pore water pressure in some degree,among which the pipe-pile group penetrated in a radial way has the least peak of excess pore water pressure,and the dissipation rate is the fastest,which is the most favorable for reducing the squeezing effect of the sinking piles,and pile sinking effect is the best.