旧路拓宽工程的病害特征和机理

以重庆市和上海市为依托,对山区和平原地区的旧路拓宽工程及其相关病害进行系统的调研和分析.结果表明,旧路拓宽工程中的新老路基结合方式主要取决于地形地基条件、拓宽范围、新路基填挖形式、新老边坡类型和新老路基共同作用层厚度5大分类因素;旧路拓宽工程的病害主要表现为路基、路面和支挡结构的损坏,以及路面整体性能的下降;病害的成因往往是多方面的,但新老路基之间的不良结合和不协调变形是最根本的,也是旧路拓宽工程中的主要控制机理.

On Distress Characteristics and Mechanism in Road Widening Engineering

When the width of a road is insufficient to meet current National Highway Standards or the need of increased traffic loading, it will be widened. But some facility distresses often appear in road widening engineering, especially the pavement distresses near the position of existing-widening subgrades integration. Several existing widened roads in Chongqing and Shanghai were chosen to investigate the facility distresses in road widening engineering. Based on the investigation and a classification of the combining modes between the existing subgrade and the widening one,the distress characteristics and mechanism in road widening engineering are proposed in this paper. It is shown that the distress resulted essentially from the instable integration and the incoordinate deformation between the existing subgrade and the widening one.