三维地质结构模型中闭合地质块体的构建

Sealed Geological Block Modeling in 3D Geological Structural Model

三维地质建模中现有地质闭合区块搜索算法基于网格单元间的拓扑进行拓扑搜索,面临着拓扑信息冗余、计算量大、计算复杂度高等缺点.针对这一问题,以搜索拓扑封闭三维地质区块作为研究目标,提出一种适合表达地质界面复杂拓扑关系的拓扑模型,并在该模型上实现快速地质闭合块体搜索.由于地质闭合区块的搜索本质上应该在拓扑空间进行,因此分别定义了拓扑分界点、拓扑分界线、拓扑分界面片、拓扑分界面、闭合区块来表达复杂的地质模型在拓扑空间中的结构,将几何空间与拓扑空间分开表达存储,并在构建过程利用地质曲面的边界信息,遵从点、线、面、体的顺序逐级进行构建:依据拓扑分界点定义在三维曲面边界信息中构建拓扑分界点;在2个拓扑分界点间构建拓扑分界线并填充其拓扑信息;在拓扑分界面上追踪由拓扑分界线组成的封闭拓扑分界面片;对全局拓扑分界面片进行拓扑分析得到闭合区块.实例测试表明,由于拓扑模型的构建过程只利用了地质曲面的边界信息,因此构建过程快速,大大简化了识别的复杂度,可以满足任意复杂曲面间的接触关系的处理,也就从理论上解决了任意复杂的三维地质闭合区块的快速识别问题.

In 3D geological modeling, the existing geological sealed block recognition algorithms were based on topology between cells of geological surfaces. These algorithms faced some obvious weaknesses such as topology data redundancy and high computational complexity. To solve these problems, with research objective of recog-nizing topological closed 3D geological blocks, this paper presented a topology model that is suitable for ex-pressing complex topological relationship between geological surfaces to separate geometry and topology of geological surfaces, and proposed a rapid construction process of this model. Geological sealed block is area sur-rounded by geological surfaces that are topological closed in the underground space; therefore, geological sealed block recognition is a topological problem in essence, not relating to geometry. From the perspective of this point, the defined topology model include topological node, topological border, topological facet, topological surface, and topological block. Its construction process follows four steps: search topological node in geological surfaces boundary; construct topological border; build topological facet composed of closed topological borders; search topological block in all topological facets. When searching geological sealed blocks, the built topology model transfers searching process from geometric space to topological space. The rapid construction process due to the only use of boundary information of geological surfaces during construction process of the topology model. Ex-perimental results show that this algorithm has a good performance of time complexity and can satisfy all kinds of relationship between complex geological surfaces because of the integrity of topology model in theory.