老路拼接中土工格栅治理路面结构阻裂作用分析

结合滨河路老路改造工程,应用数值仿真,引进了奇异单元模拟裂缝尖端的应力应变场,建立了土工格栅治理新老路路面拼接的计算模型,对行车荷载偏载作用下老路拼接工程中土工格栅的阻裂作用进行分析。结果表明:老路拼接裂缝为张拉型,应力强度因子KI远大于KII,拼接位置主要发生弯拉破坏;新老路不均匀沉降作用下,铺设土工格栅应力强度因子小于未铺设土工格栅应力强度因子,土工格栅阻止裂缝的扩展,对路面裂缝有阻裂作用;在新老路路面拼接处,半刚性基层开裂先于面层,土工格栅铺设位置越靠上,越有利于发挥土工格栅的抗拉效果,建议在路面基层顶面铺设土工格栅。

Pavement Crack Resistance Effect Analysis of Geogrid Treatment in Old Road Widening

Combined with the old road reconstruction project of Riverside Road,numerical simulation has been conducted and singularity unit has been adopted to simulate the stress-strain field of crack tip.A calculation model of the joint of the new and old road at geogrid is established to analyze the pavement crack resistance of geogrid treatment in old road widening.The result shows:old road widening crack is of tension type,whose stress intensity factor KⅠ is far greater than KⅡ,and the widening position mainly has tension failure.Under the differential settlement effect of the new and old road,the strength factor of paved geogrid is smaller than that of non-paved geogrid,so geogrid can stop the expansion of crack and has a resistance effect on the pavement crack.At the joint of the new and old road,crack of semi-rigid base is earlier than surface course,and if geogrid pavement position is closer to the top,it will be more in favour of the tense-resistance effect of geogrid,so it id recommended to pave geogrid on the surface of semi-rigid base.