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piles in high and steep slope areas
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(西南交通大学 土木工程学院，四川 成都 610031)
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高陡斜坡区基桩水平承载特性模型试验研究
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WANG Yuanyuan，DENG Ronggui，GUO Tao，WANG Wenpo，ZHANG Jin
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Model test study on horizontal bearing characteristics of foundation
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王园园，邓荣贵，郭 滔，王文坡，张 晋
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Key words：pile foundations；model test；bearing characteristics；ultimate bearing capacity；horizontal static loading test；combined loading；multivariate fitting
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关键词：桩基工程；模型试验；承载特性；极限承载力；水平静载试验；组合加载；多元拟合
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摘要：凭经验建造的高陡斜坡区桥梁基桩因水平作用引起病害的情况越来越多。为此，以红顶特大桥为原型，设计一套加载装置和试验方案，考虑基桩位于边坡中的位置与受力形式2个因素，对基桩水平承载特性进行水平静载与轴–横向组合加载模型试验研究并分别得到桩顶位移，水平荷载与相对位置及竖向荷载的拟合关系。结果表明，水平循环荷载作用下，桩顶水平位移与桩身弯矩均随荷载及其循环作用次数的增大而增大；水平荷载作用下，基桩水平极限承载力与其所在位置距坡脚的水平距离呈反比，即基桩越靠近坡脚线，其水平极限承载力越大，同时桩顶水平位移、桩身弯矩则越小；水平与竖向同时加载对基桩水平极限承载力的影响，与预加竖向荷载是否达到基桩竖向变形稳定荷载临界值有关，竖向荷载小于该临界值时，可提高基桩水平极限承载力，竖向荷载大于该临界值时，会降低基桩水平极限承载力。
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(School of Civil Engineering，Southwest Jiaotong University，Chengdu，Sichuan 610031，China)
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Abstract：There are more and more diseases caused by the horizontal action of bridge foundation piles built by experience in high and steep slope areas. In this paper，a set of loading devices and test scheme were designed with the Hongding bridge as the prototype. Considering the position of the foundation piles in the slope and the stress form，the horizontal static loading and lateral-axial combined loading model tests were conducted on the horizontal bearing characteristics of the foundation piles，and the fitting relationships of the pile top displacement，the horizontal load，the relative position and the vertical load were obtained，respectively. The results show that under the horizontal cyclic load，the horizontal displacement of the pile top and the bending moment of the pile body increase with the increase of the load and the load cyclic action times. Under the horizontal load，the ultimate bearing capacity of the foundation pile is inversely proportional to the horizontal distance between its position and the slope toe. That is，the closer the foundation pile is to the slope toe，the greater the ultimate bearing capacity，while the horizontal displacement of the pile top and the bending moment of the pile are smaller. The influence of simultaneous horizontal and vertical loading on the horizontal ultimate bearing capacity of the pile foundation is related to whether the pre-added vertical load reaches the critical value of the stable vertical deformation load of the foundation piles. When the vertical load is less than the critical value，the horizontal ultimate bearing capacity of the foundation piles can be increased；When the vertical load is greater than the critical value，the horizontal ultimate bearing capacity of the foundation piles would be reduced.
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中图分类号：TU 47 文献标识码：A 文章编号：1000–6915(2022)07–1466–10
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2022, Vol. 41 
