Based on field test results, a three-dimensional finite element method was set up to explore the settlement of the pile foundation, the bending moment of the piles, the horizontal movement of pile head, shear force and earth pressure on pile shafts with increasing embankment load behind the abutment wall. The results show that the calculated and measured results agree well; the lateral deformation of pile head and maximum bending moment of pile with the increase of embankment load increases linearly. In 20 m depth, the distribution of shear force along the pile depth is in "S" shaped pattern, the distribution of the earth pressure along the depth direction is of a parabola. The mechanical model of low-cap pile foundation is equivalent with the statically indeterminate beam of the pile head and pile embedded in a certain depth soil. The conclusions can be helpful and give references for pile design and construction.%基于现场测试结果,采用三维有限元技术分析低承台桥台桩基在台后路基填土过程中桩基沉降、桩身弯矩、桩顶水平变形、桩身剪力和桩侧附加水平挤压力随台后填土荷载增加的变化规律.研究结果表明:计算结果与实测结果吻合较好:桩顶水平变形和桩身最大弯矩随填土荷载的增加近似呈线性增加:深度方向20m范围内,桩身剪力图呈“S”型,桩侧附加水平挤压力图呈抛物线型.低承台桥台桩基力学模型等同于桩项和桩端嵌入一定深度、具有一定变位的超静定梁结构.本文所得结论可以为桥台桩基的设计和施工提供参考.
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