摘要：The railway 3D visual design plays an important role in checking the rail projects and improving the quality of railway design, because the key to implement Railway a 3D visual design is to build a 3D model of railway line landscape. The study on the methods of building a 3D model of railway line landscape is of important academic significance and practical value. We constructed a 3D digital terrain model with aerial survey Data or manual survey data in the regional railway, utilizing plan, profile, cross section data and bridge, tunnel, railway bed data to create the 3D railway line model and merging the two models to form a 3D model of railway line landscape. Based on analyzing the algorithms of Delaunay triangulation creation in Domestic and abroad, in view of the situation of building DTM and the need of realizing railway 3D visual design, a divide and conquer algorithm of building DTM is presented. The algorithm uses square grids to manage disordered points, to form triangular meshes in grids, DTM can be obtained by merging the triangular meshes so that the work of sorting the disordered points before building DTM is reduced greatly; moreover, the algorithm utilizes sub area to control the vertices of convex hull so that the range can be predefined when searching support points, the workload of searching support points reduced and the speed of merging two triangulations raised. A method for inserting constrained boundaries in DTM based on the study of the generation of constrained Delaunay triangulation is presented. First, we searched for the diagonals not intersecting with the constrained boundaries. Then we used them to cut the influenced area. The method has the advantages of a plain principle and a fast speed. The method of utilizing plan, profile, cross section data and digital terrain model to establish the 3D model of the main construction of railway line and the terrain model is presented. It describes the irregular entity surfaces by cutting them into

摘要：随着时代的进步,计算机应用技术得到了广泛使用。因此有了数字地面模型,也有了道路路线辅助设计。从此野外道路的勘测工作效率以及质量都有了很大的提高。就公路勘测与设计一体化技术进行探讨。

摘要：介绍了市政道路路线CAD系统的主要功能和实现机理,使用结果表明,该系统具有适应能力强等优点,可为公路设计和快速软件开发人员提供有益启示。

摘要：公路设计主要突出线性设计。在地形复杂的山区路段，设计师对道路的路线细节和立体线形难以把握．这需要借助和结合可视化技术进行分析来确定。而建筑信息模型（BIM）技术的可视化，在此方面有较大优势。本文简要论述TBIM在道路路线设计、纵断面设计和平纵组合视觉分析中的应用情况，并对其优缺点进行分析。

摘要：土方量计算是工程设计的重要内容，也是施工费用估算的重要依据，因此对于工程设计有着十分重要意义。土方计算的目的主要是计算同一地块开挖（或填充）前后的填方量（或挖方量），实际上就是计算体积。传统计算方法有方格网法、断面法、等高线法等，由于计算机技术与地理信息系统（GIS）技术的发展，又发展了基于数字地面模型的计算方法。