基于有限杆单元法的陡坡段桥梁基桩受力分析

发布时间：2018-02-20 02:12

本文关键词： 桥梁工程桩基础有限杆单元法高陡斜坡 “P-Δ”效应　出处：《中国公路学报》2014年06期 　论文类型：期刊论文

【摘要】：为了对山区高陡边坡桥梁桩基进行合理分析,提出了一种改进有限杆单元法。首先,对通用杆系有限单元法的单元刚度矩阵进行修正,以综合考虑"P-Δ"效应及桩土相互作用对桩身内力和位移的影响。在此基础上,根据陡坡段基桩不同特征段的受力变形特点,将基桩划分为自由段、受荷段和嵌固段,并对桩身荷载及边界条件进行处理,建立了适用于高陡边坡桥梁桩基内力位移分析的改进有限杆单元法,并以MATLAB为平台编制了相应的计算程序。最后,结合某工程实例,重点分析了剩余下滑力大小、桩顶荷载形式等因素对基桩内力及位移的影响。研究结果表明:理论计算值与室内模型试验的实测结果吻合较好,最大相对误差在10%以内,表明该方法正确、可行;高陡边坡条件下桥梁基桩桩顶荷载对桩身内力有显著影响,"P-Δ"效应明显,在实际工程中应对其予以考虑。
[Abstract]:In order to reasonably analyze the pile foundation of high and steep slope bridge in mountainous area, an improved finite member element method is proposed. Firstly, the element stiffness matrix of the universal finite element method is modified. Considering the "P- 螖" effect and the influence of pile-soil interaction on the internal force and displacement of the pile, the pile is divided into free section, loaded segment and fixed segment according to the deformation characteristics of different characteristic sections of the pile in steep slope section. The improved finite bar element method is established for the analysis of internal force displacement of pile foundation of high steep slope bridge, and the corresponding calculation program is compiled on the platform of MATLAB. Finally, combined with an engineering example, the finite bar element method is developed for the analysis of the load and boundary condition of the pile body, and the method is applied to the analysis of the internal force and displacement of the pile foundation. The influence of residual sliding force and pile top load on the internal force and displacement of foundation pile is analyzed. The results show that the theoretical calculation value is in good agreement with the measured results of indoor model test, and the maximum relative error is less than 10%. The results show that the method is correct and feasible, and that the load on the top of pile of bridge foundation has a significant influence on the internal force of pile body under the condition of high and steep slope, and the "P- 螖" effect is obvious, which should be considered in practical engineering.
【作者单位】：湖南大学岩土工程研究所;
【基金】：国家自然科学基金项目(50878083) 交通运输部西部交通建设科技项目(2008 318 785 31) 湖南省研究生科研创新项目(CX2011B160)
【分类号】：TU473.1

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