新老路基工后差异变形对路面结构的影响

Influence of Pavement Under Discrepant Deformation After Construction Between Existing Subgrade and That to Be Widened

路基拓宽工程中相关病害的发生与新老路基间的工后差异变形有着直接的关系,通过有限元数值模拟和室内足尺试验,对沥青路面在路基差异变形下的结构响应进行了深入分析,为相关工程设计方法的建立提供重要的理论依据和技术支持.理论分析表明,较小的路基不协调变形足以使沥青混凝土路面在路面结构中产生较大的附加应力,应力级位明显上升.室内足尺试验研究表明,在发生路基不协调变形后,新路基处的沥青路表当量回弹模量和疲劳寿命均有不同程度的下降.

The distresses such as lognitudinal fissures often appear in road widening engineerings.Investigation and study show that the discrepant deformation after construction between the existing subgrade and the one to be widened is the main reason.Through studies on computation models of asphalt pavement construction's response to uncoordinated deformation,we figure out the increasing stress of each pavement layer.Under the indoor large scale test,the resilient modulus of pavement and it's fatigue life are reduced respectively.Meanwhile the reduction is obviously smooth by glass fiber grid reforcement in asphalt pavement.