基于多源数据和先验知识约束的复杂地质体三维建模研究

Research on 3D geological modeling of complex geological body based on multi-source data and prior geological knowledge

三维地质模型可以直观的展现地下地质情况,对传统地矿行业的转型升级和城市规划建设都具有重要意义。针对复杂地质条件下三维模型的构建,笔者等提出了一种基于多源数据和地质先验知识约束的三维地质建模方法。以成都市为例,基于MapGIS10.0软件三维地学建模模块,在DEM数据、数字地质图、综合地质剖面图、钻孔数据、物探解译数据、构造纲要图等多源数据,以及地质体展布形态、产状和厚度变化,断层性质、延伸方向、产状变化、对地质体的错切,褶皱类型、形态特征、两翼产状变化等地质先验知识的共同约束下,开展复杂地质条件下三维地质模型构建研究。笔者等详细介绍了复杂地质体三维建模数据源的准备、建模流程与方法、模型的构建与可靠性分析。认为采用分块建模技术可有效降低复杂地质体三维模型构建的难度,提高建模效率,实现模型的无痕拼接,且易于后期模型的修改完善。本次基于多源数据和地质先验知识约束,采用分块建模技术首次构建了成都市三维地质模型。笔者等通过地质先验知识(地质规律)和静态数据(可视化和抽稀钻孔数据)对模型的可靠性进行了分析,其中抽稀钻孔数据分析采用未参与建模的真实钻孔对三维地质模型中地质体埋深和分层厚度进行误差计算,获得地质体埋深误差均值为33.15 m,分层厚度误差均值21.37 m,认为模型的可靠性较高,可为成都市城市规划和重大工程选址提供重要的基础地质数据支撑。

Objectives:Visualization of the three-dimensional geological model for the underground geological conditions is of grea t significance to th e transformation and upgrading of the traditional geology and mineral industry, urban planning and construction.For constructing a 3D model under complex geological conditions, a 3D geological modelingmethod based on multi-source data and geological prior knowledge constraints is used in this paper.Methods:Taking Chengdu as an example, we applied a 3D geological modeling module of the Map GIS10.0 to buildthe 3D geological model through integrating all the complex geological information concerning the DEM data, digital geological map, comprehensive geological profile, borehole data, geophysical interpretation data, structural outlinemap, as well as prior knowledge such as geological body distribution form, attitude and thickness change,fault geolo characteristic, gicalextension direction, attitude change, staggered cutting of geological body, fold type, morphologicalcharacteristics, attitude change of two wings etc.T his paper explicates the detailed model building process i ncluding the preparation of 3D modeling data source ofcomplex geological body, modeling process and method,mode l construction and reliability analysis.Results:We proposed that the block modeling technology can effectively reduce the difficulties of building a three-di mensional model of a complex geological body, improve the modeling efficiency, and realize the traceless splicingof the model, while it would be easier to modify and improve the model at a later stage.Based on the constraints of multi-source data and geological prior knowledge, the block modeling technology is first used to constructthe three-dimensional geological model of Chengdu.Conclusions :We examined the de pendability of the model through geological prior knowledge(geological rule)and static data(visualization andreal sparse drilling data which does not participate in the modeling) to calculatethe error of the ed depth and layered thickness of the geological body in the three-dimensional geologicalmodel.Finally, buit rishows that the average err or of the buried depth of the geological body is 33.15 m and the average error of the layered thickness is 21.37 m,which suggests that the model has high reliability and can provide important basic geological data support for Chengdu urban planning and major project site selection.