高斯投影变形对高速铁路线路设计的影响

Deformation Effect Caused by Gauss Projection on Track Design of High-speed Railway

研究目的:我国高速铁路工程测量平面坐标系采用工程独立坐标系统,投影方式为高斯投影。通常把高速铁路平面坐标系划分为若干个投影分带,以满足投影长度的变形值不大于10 mm/km的要求。大家普遍认为高斯投影后角度不变,但在高速铁路线路设计中却发现高斯投影可引起相邻投影带间的角度变形。需要研究此问题对高速铁路线路设计的影响,并提出相应的解决办法和建议。研究结论:高斯投影在不同中央子午线的坐标投影带间会产生角度变形,对高速铁路线路设计产生不利影响,特别是高速铁路直线边较长,此影响不能忽视;可以通过优化工程独立坐标投影分带的位置、控制相邻投影带间中央子午线的跨度及角度变形值的大小等办法来减小对高速铁路线路设计的影响;应积极开展工程测量投影模型和计算方法研究,最终实现一个项目不换带或少换带的目的。

Research purposes： The engineering survey plane coordinate system for high-speed railway adopts engineering independent coordinate system and the projective way is gauss projection in China.Normally,the plane coordinate system for high-speed railway is divided into some subdivisions of projection,so that the deformation value of the projected side length is not more than 10mm/km.It is known that the angle will be indeclinable after conducting the gauss projection,but it was found that the angle of the adjacent projection division would be anamorphic after conducting gauss projection in the track design of high-speed railway.So it is necessary to research the effect of this problem on the track design of high-speed railway to give the corresponding solutions and suggestions to this problem.Research conclusions：The angle deformation will appear when gauss projection is used in coordinate projection division of the different central meridians,which has a negative impact on the tack design of high-speed railway.Especially when the rectilineal side of high-speed railway is very long,this negative impact can not be ignored.This impact on the track design of high-speed railway should be reduced by some ways,such as optimizing the position of the subdivision of projection of engineering independent coordinate and controlling the deformation sizes of the central meridian span and angle of adjacent gauss projection divisions.And also it is necessary to research the projection model and calculation method for the engineering survey to achieve the goal that only one projection division is used in a engineering project or fewer divisions are used in one engineering project.