路堤荷载下地基的侧向变形计算分析

目前关于路基侧向变形研究，大都是基于现场测试或数值模拟，却鲜有理论上的计算与分析。为深入研究路堤荷载下地基的侧向变形，基于布辛奈斯克等弹性理论解及平面应变问题，推导出无限长线荷载、均布条形荷载、三角形分布条形荷载及梯形分布条形荷载下地基侧向变形解析表达式，并与有限元数值计算结果对比验证了解析解的正确性。在此基础上，重点分析了土体的泊松比、路堤宽度以及路堤边坡宽度等参数对地基侧向位移场的影响。计算结果表明，路堤荷载下地基同一垂直线上土体的侧向变形沿深度呈弓形状，变形最大值在地表下某深度处。泊松比对地基侧向位移有较显著的影响：在坡脚附近地表浅层处，随着泊松比的增加，土体侧向变形的方向由向路堤内逐渐转为向路堤外；另泊松比越大，土体的水平位移也相对越大，且最大位移发生位置逐渐上移。研究结果可为类似路堤工程地基变形分析及稳定性控制监测提供一定理论支撑。

Calculation and analysis of lateral deformation of ground under embankment load

At present, the research of subgrade lateral deformation mostly focuses on field test or numerical simulation, but few on theoretical calculations and analysis. To deeply investigate the lateral deformation of ground, the analytical expressions of the lateral deformation of ground under the infinite long line load, uniform strip load, triangular distribution strip load and trapezoidal distribution strip load are derived on the basis of elasticity solution of J. V. Boussinesq and plane strain problem. Compared with the finite element numerical results, the analytical solutions are verified. On this basis, the influence of the Poisson's ratio of soil, the width of embankment and slope of embankment on the lateral deformation field are mainly analyzed. The result of calculation shows that the lateral deformation of soil on the same vertical line under the embankment load is bow-shaped along the depth and the maximum deformation is at a depth below the ground surface. The Poisson's ratio has a significant effect on the lateral deformation of ground: in the shallow soil near the slop foot, the direction of lateral deformation of ground is gradually transferred from the inside embankment to the outside because of the increase of Poisson's ratio of soil; In addition, the higher the poisson ratio is, the more the horizontal displacement of the soil will have, and the maximum displacement moves up gradually. The results can provide some theoretical support for the deformation analysis and stability monitoring of similar embankment engineering.