复杂荷载下横坡段桥梁桩基承载特性试验研究

发布时间：2018-07-23 13:00

【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。
[Abstract]:On the basis of similar theory, considering the influence of slope and height of pier column, a double pile foundation model test of bridge in cross slope under complex load is designed and completed. It is found that the vertical and horizontal combination load of the top can cause "eight" shaped cracks on the slope of the 2~5 pile diameter range, and the bridge double in the cross slope under the complex load. The failure mode of pile foundation mainly consists of the lateral displacement of the slope leading to the skew of the pier column and the large deformation of the pile. The comparative analysis of the experimental results shows that the horizontal displacement of the top is about 2 times the horizontal displacement of the pile top, and the difference of the bending moment distribution of the post pile body is significant with the double row gate type anti slide pile, and the upper part of the pile has a larger negative bending moment and the top boundary of the double pile. The horizontal displacement of the pile, the top of the column and the maximum bending moment of the pile are nonlinear growth with the increase of the slope of the slope, while the increase of the height of the pier is nonlinear. The bending moment of the pile body is obtained by the regression analysis of the bending moment of the pile body. The length of the post pile is more than that of the h, and the length of the column pile is more than that of h/l. The fitting formula of vertical load P2 on the top of the slope, and the correlation index R2 is greater than 0.9.
【作者单位】：湖南大学;
【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)
【分类号】：U443.15;U441.2

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