高陡斜坡上的桥梁桩基,除了承受上部结构荷载外,还将承受山体变形产生的剩余下滑力和桩周岩土体抗力.首先,将上部结构作用简化为桩项竖向荷载、水平荷载以及偏心弯矩,基于Winkler弹性地基梁理论,建立考虑桩-土-坡相互作用的简化受力模型.进而导出高陡斜坡上桥梁桩基各特征桩段的平衡微分方程,并采用幂级数法对其进行求解,计算结果与文献值吻合较好,说明了幂级数解答的合理性.在此基础上,分析3个主要因素对桩基内力与变形的影响.结果表明:桩项水平荷载对基桩的力学性能影响较大,高陡斜坡上桥梁桩基的陡坡效应不容忽视,选择合理的桩基直径以及采取可靠的边坡防护措施均能提高基桩抵抗弯矩和变形的能力,这些结论均可为实际工程设计提供参考.%The bridge piles in high and steep slopes not only bear the loads from the superstructure, but bear the residual sliding force and the resistance from the slope. The loads from the superstructure can be simplified as vertical loads, horizontal loads and eccentric moments, the interaction model of piles-soils-slopes and the equilibrium differential equations of the pile was established base on the Winkler elastic foundation beam theory. And then the power series method was applied to solve the equations. Afterwards, some factors which may influence the inner force and deformation of the pile were analyzed. The results show the lateral loads of the pile head have great influence on the mechanical properties of the pile; the steep slope effects of the pile are indispensable; reasonable diameter of the pile and reliable protection measures for the slope can improve resistance to bending and proportion of the pile. All of these conclusions can provide reference for practical engineering design.
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