山区超高加筋土路基力学行为的有限元分析

以十堰至房县高速公路为例, 采用弹塑性有限元程序, 对山区某超高加筋土路基修筑过程中的双向位移、土压力、剪应力以及加筋体轴力与位移分布等力学行为进行数值分析。研究结果表明:① 加筋体内及加筋体后填土内侧向土压力不大, 垂直土压力主要为填土自重应力;② 加筋土路基底部混凝土圬工挡墙承受较大的侧向压力, 墙趾承受较大的压力与剪应力, 应保证基础平台的稳定性;③ 加筋体最大拉力出现在路基底部, 墙面最大水平位移出现在路基中部, 底部格栅后端承受一定的压应力, 可通过对混凝土圬工挡墙后的填土进行压实控制。研究成果可为山区超高加筋土路基设计方案提供参考, 同时对其他类似工程的数值分析具有一定的理论借鉴意义。

Finite Element Analysis on the Mechanics Behavior of Super-high Reinforced Earth Embankment in Mountainous Areas

The bi-directional displacements, earth pressure, shear stress, geogrids’ axial stress distribution and displacement distribution of a mountainous super-high reinforced embankment were systematically analysed using an elastic-plastic finite element program. The highway from Shiyan to Fangxian was taken as a case study. Results showed that: (1) The lateral earth pressure in geogrids and fills was small, and the vertical earth pressure mainly came from the gravity stress of the fill. (2) The lateral pressure in the concrete masonry retaining wall was large, and the toe of wall bore large pressure and shear stress, so the stability of the foundation should be guaranteed. (3) The maximum tension of the geogrid lied on the bottom of the embankment; the maximum horizontal displacement of the wall face was located on the middle of the embankment. Compressive stress was found at the bottom of the geogrid back-end, which can be decreased by controlling the fill compaction quality. These research results provide references for the design of super-high reinforced embankment in mountainous area, and is of theoretical significance for other similar works.