新疆地区基层开裂工况下沥青路面力学响应

Mechanics Response of Asphalt Pavement based on Substrate Cracking Conditions in Xinjiang Region

新疆特殊的大温差环境加之交通荷载的综合作用,致使该地区水泥稳定类基层出现大面积的裂缝病害,危及路面耐久性。该研究针对新疆特殊气候及交通条件,就沥青路面抗裂结构开展系统研究。利用有限元软件建立各类路面抗裂结构模型,进行大量理论计算与深入分析。结果表明:基层开裂工况下,复合式柔性基层路面结构沥青层抗拉伸性能受荷载作用位置影响较小;超载情况下,半刚性基层结构路面更容易产生剪切破坏;极端低温环境下,半刚性基层结构路面抗裂能力不足,加厚式复合式柔性基层将会减缓路面开裂,倒装结构路面受降温幅度影响最大;复合式柔性基层路面结构在裂缝宽度为6 mm左右时层底拉应变最大,半刚性基层路面结构在裂缝宽度为10 mm以下时受裂缝宽度影响较大。

The special environment of Xinjiang with large temperature difference coupled with the combined effect of traffic load has caused large cracking defects in the cement stabilized base layer in the area,which endangers the durability of the pavement.This study conducts a systematic research on the crack resistance structure of asphalt pavement for the special climate and traffic conditions in Xinjiang.The finite element software is used to establish various types of pavement anti-cracking structural models,and a large number of theoretical calculations and in-depth analyses are performed.The results show that the tensile performance of the asphalt layer for the composite flexible subgrade pavement structure is less affected by the location of the load action under the condition of the subgrade with cracks.Semi-rigid base structure pavements are more prone to shear damage under overload conditions.In extreme low temperature environment,semi-rigid base structure pavement has insufficient resistance to crack,thickened asphalt layer for the composite flexible subgrade pavement structure will slow down pavement cracking,inverted structure pavement is most affected by the temperature reduction.The tensile strain at the bottom of the layer for the substructure is maximum at a crack width of about 6 mm,the semi-rigid base pavement structure is more affected by the crack width when the crack width is 10 mm or less.