群桩沉桩引起的超孔隙水压力的室内模型及试验分析  

MODEL TEST AND ANALYSIS OF EXCESS PORE WATER PRESSURE PRODUCED BY DRIVING PILE GROUP

作　　者：张建新[1] 赵建军[1] 孙世光[1] 

机构地区：[1]天津城市建设学院天津市软土特性与工程环境重点实验室,天津300384

出　　处：《工业建筑》2009年第1期76-78,共3页Industrial Construction

基　　金：天津市自然科学基金资助项目(06YFJMJC05700)

摘　　要：基于群桩模型试验,分别对单桩和群桩沉桩时引起的超孔隙水压力的变化情况进行量测,并对超孔压的分布、消散和施工顺序的影响给予分析。试验结果表明:随着沉入土体内桩数的增加,超孔隙水压力不断积累,但累积到一定程度后增幅变缓。沉桩顺序对超孔隙水压力有影响。在水平方向,随着测点至桩轴距离的加大而呈非线性减小,超孔压的影响范围约在5倍桩径内;在桩群范围内,超孔隙水压力沿深度是不断增加的,且外侧增加幅度大于桩群区域。超孔压的消散与土体的渗透性有关,消散要经过一个缓慢的过程,群桩施工时要注意采取能使孔隙水快速排出的措施,以减小沉桩挤土效应。Based on model test of pile group, the changes in excess pore water pressure are measured as single pile and pile group are pressed; the dissipation and distribution of excess pore water pressure as well as effect of construction order are analyzed. The excess pore water pressure is continuously accumulated with increasing of pile＇s number, but this tend is getting slower. In horizontal direction, excess pore water pressure nonlinearity decreased with increasing of the distance between measuring point and pile＇ s axis. The effect range of excess pore water pressure is within 5D （ herein D is the diameter of pile）. The excess pore water pressure continuously increased along depth and the increment of lateral side is much greater than that in the region of pile group. The dissipation of excess pore water pressure is related to the soil＇ s permeability and dissipation is a slow process. Measures for discharging pore water should be adopted to reduce soil squeezing effect in pile group construction.

关 键 词：群桩 挤土效应 模型试验 超孔隙水压力 

分 类 号：TU473.1[建筑科学—结构工程]