黑龙江交通科技

为了保证公路改扩建项目的设计质量，以G318国道武汉至仙桃段改扩建项目为例，对路线开展现场测量，基于测量的散点数据拟合纵断面线形。随后，对比了纵断面竖曲线的拟合方法，选择二次抛物线函数拟合竖曲线，并在拟合线形时约束纵坡坡长、坡度及竖曲线半径等参数。纵断面拟合后，发现局部路段的纵坡较大、凸形竖曲线半径不足等，通过调整线形将纵坡降低至≤3%，将凸形竖曲线半径提高至≥17 000 m。纵断面线形调整后，将公路划分若干评价单元，基于运行速度评价了纵断面设计质量，发现设计速度和运行速度的差值<10 km/h，满足规范要求。

In order to ensure the design quality of highway reconstruction and expansion project, taking the Wuhan-xiantao Section of G318 highway as an example, the field measurement of the route is carried out, and the longitudinal profile alignment is fitted based on the measured scattered data. Then, the fitting methods of vertical curve are compared, and the quadratic parabolic function is selected to fit the vertical curve, and the parameters such as longitudinal slope length, slope gradient and vertical curve radius are constrained when fitting the line shape. After fitting the longitudinal section, it is found that the longitudinal slope of the local section is large and the radius of the convex vertical curve is insufficient. By adjusting the alignment, the longitudinal slope is reduced to less than 3%, and the radius of the convex vertical curve is increased to more than 17 000 m. After the alignment adjustment of the longitudinal section, the highway is divided into several evaluation units, and the design quality of the longitudinal section is evaluated based on the operating speed. It is found that the difference between the design speed and the operating speed is less than 10 km/h, which meets the requirements of the specification.