     Transfer Matrix Method for Analysis of Stress and Deformation of Bridge Piles in Sloping Ground

DOI：

 作者 单位 邮编 尹平保 长沙理工大学 土木工程学院 410114 王翱 长沙理工大学 土木工程学院 赵衡 湖南大学 岩土工程研究所 杨铠波 长沙理工大学 土木工程学院 赵明华 湖南大学 岩土工程研究所

根据斜坡段桥梁基桩的水平承载特性,建立了考虑斜坡效应的桩-土相互作用模型及挠曲微分方程；基于m法和传递矩阵法,推导了桩身内力与位移分析的传递矩阵解答；通过模型试验,测得了黏土和砂土斜坡地基比例系数,拟合得到了斜坡地基比例系数与坡度间的关系式,验证了理论解答的合理性；以某工程实例为基础,分析了斜坡坡度和桩顶水平荷载对斜坡基桩受力与变形的影响。研究表明：斜坡地基比例系数随桩土交界面处桩身水平位移增大而呈非线性关系减小；黏土和砂土斜坡地基比例系数均随斜坡坡度增加而减小；基桩桩顶水平位移和桩身最大弯矩均随斜坡坡度和桩顶水平荷载增加而增大；当斜坡坡度由0°增加至60°时,桩顶水平位移约增大86.4%,桩身最大弯矩约增大4.6%,桩身最大弯矩位置约下移2.0m；桩顶水平荷载每增加50kN,桩顶水平位移平均增大48.5%,桩身最大弯矩平均增大41.6%。

According to the bearing characteristics of bridge piles in sloping ground, the pile-soil interaction model under consideration of the slope effect and the differential equation of flexural deformation were established. Based on the m method and transfer matrix method, the transfer matrix solution of pile internal force and displacement analysis was derived. The proportional coefficient of clay and sand slope foundation were measured by model tests. The relationship between the proportional coefficient of slope foundation and slope angles were obtained by nonlinear fitting, and then the rationality of theoretical solutions were verified by model test. Based on an engineering example, the influence of slopes and horizontal loads on the internal force and deformation of piles in sloping ground were analyzed. The results show that: the proportional coefficient of sloping ground decreases nonlinearly with the increase of horizontal displacement of pile at the pile-soil interface. The proportion coefficients of clay and sand sloping grounds decrease with the increase of slope angles. The horizontal displacement of pile top and the maximum bending moment of pile body increase with the increase of slope angles and horizontal loads. When the slope angle increases from 0° to 60°, the horizontal displacement of pile top increases by about 86.4%, the maximum bending moment of pile body increases by about 4.6%, and position of the maximum bending moment moves down by about 2.0m. When the horizontal load increases by 50kN, the horizontal displacement increases by 48.5% and the maximum bending moment increases by 41.6% on average.
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