考虑斜坡效应的基桩屈曲临界荷载分析  

Analysis of critical buckling loads of piles considering slope effect

作　　者：尹平保[1,2] 杨莹[1,2] 贺炜[1,2] 刘新喜[1,2] 赵衡[3] 

机构地区：[1]长沙理工大学土木与建筑学院,湖南长沙410114 [2]现代公路交通基础设施先进建养技术湖南省协同创新中心,湖南长沙410114 [3]中南大学资源与安全工程学院,湖南长沙410083

出　　处：《岩土力学》2017年第9期2662-2668,2675,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.51408066;No.51478051;No.51378082);湖南省教育厅优秀青年项目(No.16B013);长沙理工大学土木工程优势特色重点学科创新性项目(No.16ZDXK02)~~

摘　　要：以某实际工程桩为原型,根据相似理论设计并完成了斜坡基桩竖向承载室内模型试验,分析了不同坡度及桩长条件下斜坡基桩屈曲临界荷载,获得了基桩屈曲临界荷载理论计算公式及拟合公式。研究表明:竖向荷载作用下,基桩荷载-位移曲线均无明显拐点,且桩顶沉降、水平位移均随坡度或桩长的增加而增大,斜坡基桩的屈曲失稳破坏模型非常显著。斜坡基桩的屈曲临界荷载值由桩顶沉降和水平变形共同控制,斜坡坡度越大或基桩自由段越长,其屈曲临界荷载及竖向承载折减系数越小,斜坡效应越明显。对比分析表明,由理论公式和拟合公式计算得到的结果与模型试验结果均吻合较好,最大误差尚不足10%,验证了模型试验、计算理论及拟合公式的合理性,其成果可以为实际工程设计提供参考。A model test for piles located in steep slopes has been conducted based on similarity theory.The transfer of axial loading,and the identification of critical buckling load have been investigated.The theory calculation formula and the fitting formula of critical buckling loads were obtained.The results show that there is no obvious inflection in the relationship between load and displacement.The buckling failure mode is thus dominant.Further,larger vertical and horizontal displacements of the pile top is observed in long piles.The critical buckling load simultaneously depends on the vertical and horizontal displacements of the pile top.In addition,the larger inclination the slope or the longer the free section of the pile result in smaller critical buckling load,and smaller vertical bearing reduction coefficient..The comparisons shows that the result from the theoretical calculation and the fitting formula both agree with the result of model tests,and the maximum error is less than 10%.The rationality of the model tests,the calculation theory and the fitting formula is verified.These can provide references for the practical engineering design.

关 键 词：斜坡基桩 屈曲 模型试验 临界荷载 斜坡效应 

分 类 号：TU473[建筑科学—结构工程]