地质断层三维可视化模型的构建方法与实现技术

Construction Method and Actualizing Techniques of 3D Visual Model for Geological Faults

全面而系统地研究了地质断层三维可视化构模的原理、方法及实施过程.针对地质断层三维构模的特点与要求,设计了一种基于边界表示、面向地质实体并兼顾拓扑关系的三维矢量数据模型,以有效地组织和描述包含断层的复杂地质体几何结构模型.提出了断层与地层的统一构模技术,给出了在其实现过程中所遇到的关键问题(如断层面的推演拟合、地层层面重构、断层与地层的交切处理与局部重构)的解决方案.基于断层的属性、断层数据所反映的断层面的特征和质量,应用3种方法来拟合断层面.在地层层面重构时,考虑到了断层面在地层面网格加密、插值时的约束和屏蔽作用,实现了具有多值面的逆断层网格生成技术.应用三角网切割算法TRICUT来实现断层与地层的交切处理.通过北京奥运公园场区基岩地质模型中的断层构模实例验证了这些技术方法的有效性.

A general principle, a practical method and a modeling process of 3D visual model for complex geological entities contained faults are discussed. A kind of 3D vector data model, which is based on boundary representation, suited to geological objects and their topological relationships, is developed in order to organize and describe the 3D structure model of complex geologic body. A modeling approach called the unified modeling technique for stratum and fault is presented, and some actualizing techniques are discussed. To deduce and simulate the fault plane, three methods are presented based on the basic properties, characters and qualities of geological faults reflect on fault data. For the construction of stratum surface, the restriction and the shielding action of fault plane to the interpolation process of stratum surface are considered, and the mesh generation method for multivalued surface of reverse fault is developed. TRICUT, a method to clip triangle meshes, is used to process surface cutting on stratum surface and fault plane. A concrete example of using those methods to 3D bedrock model in the Beijing Olympic Green District is presented and confirms the practical result of those techniques.