中文摘要：

铁路数字化选线设计达到实用水平的关键是复杂地质区域的数字地质选线技术。本文采用插值n次Bezier曲线和三次参数样条曲线分别实现不同类型地质对象在三维地质环境中的矢量化表达；采用CDT构建方法建立地质对象约束TIN模型，基于纹理定位和影像纹理坐标计算方法，实现栅格解译影像的定位和表达；实现将铁路数字化三维选线的矢量数据、栅格数据一体化的三维地质环境建模方法。根据直观地质遥感解译影像，建立OBB包围盒算法，自动判断线路与地质对象的空间冲突。在三维地形环境的基础上，建立超地图模型，实现三维地质环境和三维地理信息的统一集成和应用。实例表明，本文的三维地质环境模型能够较好满足复杂地质区域的数字选线要求。

英文摘要：

The key to achieve practical use of railway digital alignment and design is digital geological alignment technology in complex geological area. The paper achieved vectorization expression of different types of geological objects in three-dimensional geological environment by adapting N times＇ interpolation of Bezier curve and cubic parametric spline curve. The constraint TIN models for geological object were established by using CDT construction method. The localization and expression of raster image interpretation were realized based on texture positioning and image texture coordinate calculation method. The modeling method of three-dimensional geological environment was achieved by integrating vector data and raster data of 3D railway digital aligment. On the basis of intuitive geological remote sensing image interpretation, oriented bounding box （OBB） algorithm was established to determine the spatial conflict between railway line and ＇geological objects automatically. The hyper-map model of three-dimensional terrain environment was established to achieve the unified integration and application of three-dimensional geological environment and three-dimensional geographic informa- tion. The examples showed the model of three-dimensional geological environment better met the requirements of the digital alignment in complex geological area.