盾构掘进引起的邻近桩基水平附加荷载分析

发布时间：2018-09-12 17:50

【摘要】：基于Mindlin基本解及弹性力学基本理论,考虑刀盘挤土效应产生的附加推力、土体地层软化特性且不均匀分布的盾壳摩阻力及土体损失等因素推导得到盾构掘进过程中邻近桩基的水平附加荷载解析解答。算例分析结果表明:在x方向上,盾构刀盘到达前,邻近桩基承受附加压力荷载;刀盘通过桩基平面后,附加荷载转为拉力;在盾尾通过后,桩身附加拉力荷载达到最大。在y方向上,土体损失是引起桩身的附加荷载的主要因素,特别是在盾尾通过桩基平面后,对应于隧道拱顶及拱底附近位置桩身分别承受较大的附加压力及附加拉力荷载,这将会导致桩基产生较大的挠曲变形、弯矩及剪力,为最不利施工工况。
[Abstract]:Based on the basic solution of Mindlin and the basic theory of elasticity, the additional thrust caused by the squeezing effect of the cutter head is considered. The analytical solutions of the horizontal additional loads of adjacent piles in the course of shield tunneling are derived from factors such as shield shell friction and soil loss due to soil stratum softening and uneven distribution. The results show that in the x direction, the adjacent pile foundation bears additional pressure load before the shield cutter head arrives; after the cutter head passes through the plane of the pile foundation, the additional load changes to tensile force; after the shield tail passes, the additional tensile load of the pile body reaches the maximum. In the y direction, the soil loss is the main factor that causes the additional load on the pile body, especially after the shield tail passes through the plane of the pile foundation, the pile body corresponding to the position near the tunnel arch top and the arch bottom is subjected to larger additional pressure and additional tensile load respectively. This will result in large flexural deformation, bending moment and shear force of pile foundation, which is the most unfavorable construction condition.
【作者单位】：南京航空航天大学民航学院;中国民航大学机场学院;浙江大学滨海和城市岩土工程研究中心;
【基金】：国家自然科学基金资助项目(41472284,U1234204)~~
【分类号】：U455.43;TU473.1

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