静压群桩沉桩挤土效应模型试验  

Model Test on Squeezing Effect in Static Pressed Pile Group

作　　者：张建新[1] 赵建军[1] 鹿群[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：《天津城市建设学院学报》2010年第2期85-90,共6页Journal of Tianjin Institute of Urban Construction

基　　金：国家自然科学基金(40972170);天津市自然科学基金(09JCYBJC07800)

摘　　要：以往对沉桩挤土效应的研究主要集中于单桩或双桩,而对群桩挤土效应的分析较少,但在实际工程中,桩基工程通常都是以群桩的形式来设计和施工的.基于室内模型试验,分析了群桩顺序压入土体后所引起的土体变形规律、超孔隙水压力的变化和沉桩前后土体的微观结构特征.试验结果表明:群桩压入后,土体水平侧移和地表隆起是不断累积的,存在着已压入桩的遮帘作用;超孔隙水压力并不是单桩引起的超孔隙水压力的简单叠加;沉桩后,土体微观孔隙的大小、形态和排列特征也发生了变化,其结构性更加紧密,挤土效应明显.In the past, the study of squeezing effect by pile driving was mainly focused on single pile or double piles, with meager research into that of the pile group. However, in practical terms, the design and construction of pile foundation engineering are usually embodied by pile group. Based on the indoor model test, the soil deformation caused by group pile pressing, excess pore water pressure and micro-structural characteristics of soil have been analyzed. The test result shows that the soil horizontal displacement and land upheaval accumulate continuously, with sheltering effects after pile pressing. Excess pore water pressure is not the simple stacking of the pressure of each pile. With the pile being driven, and the change of the size, appearance and arrangement character of micro-pore, soil＇s structure gets more compacted, and squeezing effect becomes significant.

关 键 词：群桩 挤土效应 模型试验 

分 类 号：TU473.1[建筑科学—结构工程]