摘要
以相似理论为基础,考虑边坡坡度及墩柱高度的影响,设计并完成了复杂荷载作用下横坡段桥梁双桩基础室内模型试验。研究发现:柱顶竖向及水平向组合荷载可导致2~5倍桩径范围坡面出现'八'字形裂缝;复杂荷载作用下横坡段桥梁双桩基础的破坏模式主要是坡体横向侧移导致墩柱偏斜、基桩变形过大等。试验结果对比分析表明:柱顶水平位移约为桩顶水平位移的2倍,前、后桩桩身弯矩分布规律与双排门式抗滑桩差异显著,桩身上段均存在较大负弯矩,双桩桩顶边界条件设成弹性嵌固更为合理。桩、柱顶水平位移及前桩桩身最大弯矩均随边坡坡度θ的增加呈非线性增长,而随墩柱高度h的增加近似呈非线性增长。通过实测桩身弯矩的回归分析得到了前、后桩桩身弯矩关于横坡坡度θ、柱桩长度比h/l及坡顶竖向荷载p2的拟合公式,且相关指数R2均大于0.9。
Considering the influence of slope angles and column height,model tests of bridge double-piles foundation in cross slope under complex loads were designed and conducted based on similarity theory. It is found that around 2 ~ 5times pile diameter range,the slope appeared'Λ'crack. Under the combined loads at the column cap,the main failure mode of the models was deflection of columns and large deformation of piles due to lateral soil movement. The comparison and analysis of test results show that the horizontal displacement of columns cap is 2 times that of piles top.Pile moment of bridge double-piles in cross slope is different from that of anti-slide double-pile. Large negative moments emerged at the top of the piles,and the boundary conditions were supposed to be elastic embedding. The deformation and pile moment of front pile increased nonlinearly with θ and h. Through the regression analysis of test results,fitting formulas of front and back pile moment were respectively obtained with correlation index R2bigger than 0. 9.
出处
《土木工程学报》
EI
CSCD
北大核心
2014年第5期110-117,共8页
China Civil Engineering Journal
基金
国家自然科学基金(51278187)
交通部西部建设科技项目(200831878531)
湖南省研究生科研创新项目(CX2011B160)
关键词
桥梁工程
模型试验
双桩基础
复杂荷载
横坡
非线性分析
bridge engineering
model tests
double-piles foundation
complex loadings
cross slopes
nonlinear analysis
