近年来我国高速公路事业发展迅速，然而伴随着公路里程的增加，威胁高速公路运 输安全的公路病害亦不断增多，尤其是高填方路堤出现的沉降和边坡失稳现象尤为突 出，研究如何高效处治高填方路基中同时出现的沉降和边坡失稳问题至关重要，目前关 于微型桩在控制路基沉降中的应用有一定研究，但关于微型桩在加固路堤边坡中的理论 研究滞后于工程实践需要，因此关于微型桩在控制路基沉降和加固路堤边坡过程中的承 载特性和作用机理研究对于微型桩在公路领域的推广很有实际意义。 本文选取张涿高速公路典型高填方路堤路段出现的病害为研究对象，结合现场调 查、理论分析以及数值模拟等方法在对路基沉降和路堤边坡的稳定性进行定量评价的基 础上进行了微型桩分别在竖直荷载和水平荷载作用下承载特性分析；研究了基于FLAC 3D 的微型桩单桩在水平推力作用下的内力分布特点；模拟分析了微型桩群桩和微型桩 结合锚杆两种方案的加固效果。可得出结论：在水平荷载作用下微型桩桩身在滑面附近 出现最大正剪力和最大负弯矩，且两值均随着荷载水平的增加而增大，最大值位置向下 移动；微型桩能够控制坡体的侧向位移和剪切应变，且主要通过潜在滑面附近及以上部 分桩身来发挥作用，而滑面以下有限距离处到桩底这部分桩身主要起到控制竖向变形的 作用；微型桩对于路堤边坡的加固机理主要体现在对于水平推力的抵消作用，使得边坡 土体保持在应力平衡状态，从而维持边坡稳定；而在控制路基沉降变形过程中主要依靠 桩土接触产生的摩阻力来发挥作用。 数值模拟结果和现场监测结果表明微型桩在控制高速公路路堤沉降和加固高填方 路堤边坡过程中效果显著，综合分析认为微型桩群桩方案在加固路堤中合理、可行，本 文相关研究成果可供微型桩性状研究和类似路基加固问题借鉴参考。

Highway enterprise in our country has developed rapidly in recent years, while the threat of road disease to highway transportation safety is also growing along with the increase of highway mileage,especially the settlement of high embankment and instability phenomenon of slope is particularly prominent.Studying how to efficiently treat the high fill sub-grade sedimentation and slope instability which appear on the expressway at the same time is essential, at present research application about micro pile in the control of sub-grade settlement has got certain development, but the theoretical research on reinforcing embankment slope of micro pile lags behind the need of engineering practice, in the process of controlling slope embankment settlement and reinforcing the slope,the application study load-bearing characteristics and mechanism of action research of micro piles are of great practical significance for promotion of the application of micro piles in the field of highway. The typical high embankment section of Zhang Zhuo highway road is selected as the research object, The disease’s type and cause in Zhang Zhuo highway are analyzed and summarized combined with the site investigation, theoretical analysis and numerical simulation method, at the same time quantitatively analysis and evaluation are conducted about the settlement of roadbed and embankment slope stability; the micro pile bearing capacity is analyzed respectively under vertical load and horizontal load; the force distribution characteristic of single pile under horizontal thrust force is studied based on FLAC3D ;the reinforcement effect of the micro piles scheme and micro pile combined with anchor scheme are simulated and analyzed. Conclusions are as follows: the maximum positive shear and maximum negative moment in the micro pile occur in the vicinity of sliding surface under the horizontal load,and the two values increase with the increase of load level, at the same time their maximum values position moves down; micro pile can control lateral displacement and shear strain of the slope according to pile body near and above the potential slip surface,the vertical deformation is mainly controlled by the part of the pile that ranging from the surface under the sliding surface at a finite distance sliding surface to the pile bottom;micro pile reinforcement mechanism is to decrease the horizontal thrust force,making the slope keep in stress balance,so as to maintain the stability of the slope; the reinforcement function of micro pile depends on the friction generated by the contacting of pile surface and soil in the process of controlling of sub-grade settlement deformation. Numerical simulation results and field monitoring results show that the effect of micro piles in control of highway embankment settlement and reinforcement of high filled embankment slope effect is remarkable, the comprehensive analysis thinks that micro pile scheme is reasonable and feasible in reinforced embankment. This paper's research results can be provided for reference in micro pile properties study and similar sub-grade reinforcement study.