土工格栅加筋路堤的三维有限元分析

3D Finite Element Analysis of Embankment Reinforced by Geogrid

运用通用有限元程序ANSYS ,对软弱地基上路堤加筋的作用和效果进行了三维有限元分析 .计算中采用DP模型模拟土体的材料非线性 ,采用面—面接触单元考虑筋土界面的状态非线性 ,并采用薄膜单元来模拟土工格栅 .通过对相关参数的敏感性分析 ,证明了土工格栅模量对加筋效果有显著影响 ,并且加筋位置靠近路堤底部时更能发挥加筋性能 ;证明了在土体发生显著侧向变形时土工格栅能够发挥抗拉效果 ,从而限制土体侧向变形和路堤外侧土体的隆起 ,达到减小沉降和不均匀沉降的效果 .

Adopting the general purpose finite program ANSYS,the authors carried out three dimension finite element analysis of geogrid reinforced embankment in this paper.DP model is chosen to consider the non linearity of soil,the changing status non linearity is considered by surface to surface contact element and the geogrid is modeled by the membrane element.The analysis examines the effect of uncertainty regarding the geogrid modulus,the layers of geogrid and the material property of soft soil.It is shown that reinforcement can significantly reduce the maximum lateral deformation,vertical settlement and foundation heave,and then reduce the differential settlement.These conclusions may be useful to the design and analysis of reinforced embankment on soft soil and the interface between new and old embankments in widened embankment.