用AutoCAD辅助弯斜桥几何设计

Assisting Geometrical Design of Curved Skew Bridge by AutoCAD

对弯斜桥的几何设计 ,传统的方法是先计算再作图不但费工费力且易出错。本文介绍用 Auto CAD先作图不用计算即可直接求出座标来进行弯斜桥几何设计的方法。以广珠高速公路的某桥为例 ,在 Auto CAD中建立以点 ( 0 ,0 )为座标原点 ,竖轴为 X轴 ,横轴为 Y轴的直角座标系 ,通过已知参数将桥梁中心线、边缘线与墩台轴线及基桩布置等平面图的有关内容在 Auto CAD中绘出 ,再直接 List各点即显示出其座标。再用座标方位角法和逐桩座标表的有关桩号座标检算其结果的正确性。两种方法的结果最大正负差不超过 5mm。随着计算机在工程应用中的普及 ,可以将此方法广泛用在公路和桥梁的线形设计与施工放样中。

For the geometrical design of curved skew bridge the traditional method is to first calculate,then make the drawings.Thus it not only takes a lot of work,needs or uses great effort,but also is easy for making mistakes.The paper introduces a method by which the geometrical design of curved skew bridge can be made,i.e.it can directly get coordinate without calculation and firstly make drawing by AutoCAD.For example,in a certain bridge on the Guangzhou Zhuhai Express Highway,in AutoCAD there is established a vertical angle coordinate system which is taken the points(0,0)as the initial point of coordinate,the vertical axis is X axis and the transverse axis is Y axis.The relevant contents of the plane drawings of the bridge central line,edge lines,pier abutment axis and foundation pile arrangement etc.are drawn in AutoCAD by given parameters.Then it lists various points for showing the coordinates,and it will check the correctness of the results by coordinate azimuth method and the relevant station number coordinates of the coordinate list pile by pile.The maximum difference between positive and negative of the results of two methods shall not exceed 5 mm.With the popularization of computer in engineerng application,it could use widely the method for the alignment design and construction setting out of highways and bridges.