路堤下桩–网连接方式对筋材受力变形的影响

Influence of Pile-geosynthetic Connection Mode on the Stress and Deformation of Geosynthetic Under Embankment Loads

基于现场试验,采用有限元软件PLAXIS2D建立桩承式加筋路堤数值模型,对比分析了路堤荷载下普通加筋和固网加筋时,筋材荷载传递、变形特性及筋–土界面摩擦特性。研究结果表明:对于软土地基上高填方路堤,固网加筋能更好地发挥筋材荷载传递效应;普通加筋时筋材变形曲线可用椭圆描述,筋材下表面筋–土界面应力比n约为40%,上表面n在10%~20%之间;固网加筋时,筋材下表面n约为10%,而上表面n小于10%。基于筋材变形特性及筋–土界面摩擦特性,提出了一种筋材拉力计算方法,并通过数值模拟结果对所提方法的合理性进行了验证。

Based on field tests, a series of numerical models of geosynthetic-reinforced pile-supported embankment were established with finite element software PLAXIS2 D. The load transfer, deformation and interface friction of geosynthetic were comparatively analyzed for two kinds of reinforcement techniques, i.e., fixed-geosynthetic reinforcement(FGR) technique and conventional reinforcement(CR) technique. The results show that FGR technique can better mobilize the load transfer of geosynthetic for high-filling embankments constructed on soft ground. The deformation curve of geosynthetic can be described with ellipse for CR technique. When reinforced by CR technique, the stress ratio at the interface between geosynthetic and soil n at lower surface of geosynthetic is about 40%, however, for upper surface n is between 10%~20%. When reinforced by FGR technique, n is only about 10% at lower surface of geosynthetic, and at the upper surface n is less than 10%. A calculation method of tension in geosynthetic was proposed based on the deformation and geosynthetic-soil interface friction characteristics, the rationality of the proposed method was verified by numerical simulation results.