流塑状软土复合地基桩土相互作用机理的研究  

Study on mechanism of pile-soil interaction in liquid-plastic soft soil composite foundation

作　　者：姚建平[1] 李琦[2] 李泰灃 张千里[2] 史存林[2] 

机构地区：[1]中国铁道科学研究院,北京100081 [2]中国铁道科学研究院铁道建筑研究所,北京100081

出　　处：《铁道建筑》2015年第12期80-83,共4页Railway Engineering

基　　金：中国铁路总公司科技研究开发计划课题(2014G003-B;2014G003-D;2015G006-D);中国铁道科学研究院基金项目(2015YJ141);国家自然科学基金(51308547)

摘　　要：为解决流塑状软土地基处理中存在的问题,对单根桩在流塑状软土中的工作机理进行了有限元分析,研究了桩土模量比、桩体与滑弧切线夹角、土体抗剪强度对桩体的抗剪特性、破坏模式及桩土相互作用机理的影响。研究结果表明:桩体刚度、桩土模量差异、土体抗剪强度、桩体与滑弧切线间夹角等是影响桩体视抗剪强度(地基所提供的抗滑力减去土体提供的抗滑力)的主要因素;随着桩土模量比及桩体与滑弧切线间夹角的减小,桩体视抗剪强度逐渐增加;随着桩土模量差异逐渐增大,桩体可能发生的破坏模式依次为抗剪切破坏、受拉(压)破坏、弯曲破坏、土体绕流破坏、桩体倾倒破坏和桩体整体侧移破坏,对应不同破坏模式桩体具有不同的视抗剪强度。To solve the existing engineering problem ofliquid-plastic soft soil foundation treatment,the working mechanism of single pile in the liquid-plastic soft soil was analyzed using finite element analysis method. The influences of pile-soil modulus ratio,angle between pile and sliding arc tangent and soil anti-shear strength to pile anti-shear characteristics,failure pattern of pile and the pile-soil interaction mechanism were studied. The results show that the stiffness of pile,the modulus difference between pile and soil,the shear strength of soil,and the angle between pile and sliding arc tangent are the mainly influence factors of the ＂apparent shear strength＂,which means the difference of foundation anti-slide force and soil anti-slide force. The ＂apparent shear strength＂increased with decreasing of pile-soil modulus ratio and angle between pile and sliding arc tangent. Meanwhile with increasing of the difference of pile-soil modulus,the pile will appear different apparent shear strength corresponding to the following different failure modes such as anti-shear failure,tensile or compression failure,bending failure,soil streaming around failure,toppling failure and lateral sliding failure in sequence.

关 键 词：高速铁路 流塑状软土 桩土模量比 桩土相互作用 视抗剪强度 

分 类 号：TU447[建筑科学—岩土工程] TU473.1[建筑科学—土工工程]