旧路改建的设计方法

The Approaches for the Design of Old Highway Reconstruction

结合旧路改建的模式和特点,参考国内外的成功经验和做法,针对性地阐述了在旧路改建设计过程中的路线平面设计、纵面设计、路面加铺层设计、路面基层加铺前的预处理方法;在平面设计中,提出根据地形及旧路实际情况运用曲线型定线法,灵活运用回旋曲线及圆曲线拟合贴近实际地形的路线方案,达到降低土石方工程数量的目的,并简要介绍其定线步骤及确定回旋曲线参数A的计算方法;在路面加铺层设计中,介绍了美国的经验做法—AASHTO法的计算方法及路面加铺层的建议厚度和推荐的几种加铺层结构形式和路面基层的预处理方法。

Combined with the patterns and characteristics in old highway reconstruction as well as with reference to successful experience and practices at home and abroad, this paper illustrates the key points in the course of old highway reconstruction. The points include the design of plane, the design of vertical section, the design of road surface pavement and the pre-processing approach before pavement on the base of road surface. In the design of plane, it presents the application of curve alignment approach based on the terrain and the actual conditions of the old highway as well as the solution of curve estimation with flexible reverse curve and circle curve for the sake of reducing earthwork. It also briefly introduces the steps for alignment and the calculation method of reverse curve parameter A. In the design of road surface pavement, it introduces an American experienced practice of AASHTO and its calculation method, recommended thickness and structural forms for road surface pavement and pre-processing approaches for the base of road surface.