Abstract: The authors present a new method for three-dimensional (3D) geological modeling from a set of topological and polygonal cross-sections, and introduce topological relationships (connectivity, adjacency and inclusion) of "polygons -arcs- nodes" in cross-sections to generate Triangulated Irregular Network (TIN) by connecting adjacent open arcs instead of close contours. This method is especially suitable for cases where there are several connected polygons in a cross-section, which are general in geological applications. Besides, cross-sections are not required to be planar or parallel in this method, and topological relationships are embedded in the generalized 3D geological models. Some special ideals are also proposed for some complex geological phenomena, such as stratum dying out, faults terminated within strata, etc. Finally, a 3D geological modeling and visualization software platform was developed based on this method. A case study was conducted by using the real data at the Olympic site in Beijing, China.

Key words: 3D, geology, modeling, cross-sections, topology, topological cross-sections

摘要： 提出了一种通过引入剖面中空间要素（多边形－弧段－结点）之间的拓扑关系（邻接、关联 和包含）来生成基于边界表达的三维地质模型的方法。该方法特别适合于剖面中有多个相互 连接的地质体单元的多体建模，而该情况在三维地质建模中比较常见。同时，该方法中使用 的剖面不要求共面或者平行，拓扑信息包含于生成的三维模型中。而且，在用户少量干预的 情况下，结合地质知识，该方法可以建立绝大多数复杂地质模型。基于该方法，开发了一个 三维地质建模与可视化系统，并成功应用到北京市奥运场区的三维地质建模中，结果表明该 方法具有建立实际复杂三维地质模型的能力。

关键词: 三维, 地质, 建模, 剖面, 拓扑, 含拓扑剖面