微型桩-加筋土挡墙路基结构的模型试验研究

Model test study on Micropile-MSE Wall for subgrade

提出了一个适用于陡坡路基的微型桩-加筋土挡墙结构，为了初步检验该新型结构的有效性，通过几何相似比为10：1的缩尺模型试验，选取合适的相似材料，对三种不同加固工况的加筋土挡墙进行了对比研究．结果表明：在2—10kPa附加荷载下，较之未加固和单根竖直桩加固的挡土墙，附加荷载引起的微型桩-加筋土挡墙沉降分别减小了10．6％-40．2％和9．7％～26．4％，且附加荷载越大，减小的比例越大，而其竖直桩身弯矩则比单根竖直桩的工况减小了55．2％～77．8％；同时，倾斜桩身弯矩增量比竖直桩高出25．9％-40．3％，因而倾斜桩对挡土墙变形的控制发挥着更为重要的作用，有必要加强倾斜桩的配筋．因此，微型桩-加筋土挡墙的优越性得到了初步验证，可为其在公路建设中的应用提供参考．

The Micropile-MSE Wall suitable for subgrade in steep terrain was put forward. To verify the effectiveness of the new structure, scaled model tests with geometric similarity ratio of 10：1 were conducted to study the MSE Walls with three different reinforcement conditions. The test results indicate that compared with the unreinforced MSE wall and the MSE wall reinforced with one vertical pile, the surcharge-induced subsidence of Micropile-MSE Wall subjected to 2 - 10 kPa surcharge loadings can be reduced by 10.6% -40.2% and 9.7% -26.4%, respectively, and the reduction increases with the increase of the surcharge loading, whereas the bending moment of its vertical pile can be reduced by 55.2% -77.8% compared with that of the MSE wall reinforced with one vertical pile. In addition, the bending moment of the inclined micropile in the Micropile-MSE is 25.9% - 40.3 % higher than that of the vertical pile, showing that the inclined micropile is more important than the vertical pile in the deformation control and should be specially reinforced. Thus, the superiority of the Micropile-MSE Wall is proven, providing some references for the application in road construction.