Abstract: To resolve the problem of the complex 3D tunnel modeling generated by the changes of the tunnel sections at different rock formations during the project, the 3D tunnel modeling based on the characteristic sections was proposed. Through establishing the characteristic section model library, the 3D modeling of the changed tunnel sections was realized and the efficiency of the modeling of the complex tunnel sections was improved. Following the illustration of the data collection method and an analysis of the characteristic sections with detailed coordinates, the smoothing algorithm (smoothing the tunnel axis at the corner by an arc) of the changed tunnel sections at the corner was proposed. For the ordinary tunnel sections, the triangulation was applied in the 3D modeling; for the complex sections with simple quadrilateral structure, the 3D modeling was realized by using the Bézier surface method and the surface splicing techniques which has been validated through experiments.

Key words: 3D modeling, tunnel characteristic section, section change, topological relation, Bézier surface

摘要： 为解决巷道断面随工程需要及岩层变化不断改变，导致巷道三维建模程序复杂的问题，提出基于特征断面的巷道三维建模思想，通过建立巷道特征断面模型库，实现变化巷道段的三维建模，以期提高复杂巷道段的建模效率。首先阐述建模数据的采集方法，并对巷道断面进行了细化坐标分析；同时提出拐角处断面变化巷道段的平滑处理算法（通过圆弧来圆滑拐角处巷道中心线），对普通巷道段采用三角剖分形成三角网完成巷道段的建模；而巷道断面发生变化的复杂巷道段存在简单曲面四边形，采用Bézier曲面及曲面的拼接完成巷道段的建模,并在实验中进行了验证

关键词: 三维建模, 巷道特征断面, 断面变化, 拓扑关系, Bézier曲面