冻土地区路基融沉变形对沥青路面结构的影响

Influence of Subgrade Settlement Deformation in Frozen Soil Zone on Asphalt Pavement Structure

采用有限元方法建立了路基发生融沉变形时沥青路面结构的轴对称计算模型,将融沉变形分别简化为二次曲线和余弦曲线,分析了融沉变形对最大拉应力点位的影响,重点讨论了融沉盆形状、半径、融沉深度等因素对沥青路面结构面层和基层最大拉应力的影响。结果表明:路基的不均匀融沉变形在路面结构面层顶面产生拉应力,成为面层破坏的主要原因;在基层底面产生较大的附加应力,将会造成基层开裂,因此在多年冻土地区的路面设计中应考虑附加应力的影响。

The axial symmetry calculation model of asphalt pavement structure was built using finite element method when subgrade settlement deformation occured. The shape of subgrade settlement deformation was simplified to a conic and a cosine curve. The influence of settlement deformation on the maximum tension stress point position was analyzed. The influences of the shape, radius and depth of settlement deformation on maximum tension stresses of pavement and subgrade of asphalt pavement structure were also analyzed. The result shows that tension stress caused by subgrade non-uniform settlement deformation in the top of pavement becomes the main reason of pavement failure; much additional stress produces in the bottom of subgrade which causes subgrade crack, so the influence of additional stress should be considered in the pavement design in perennially frozen soil zone.