基于三维地质模型的岩土工程有限元自动建模方法

Automatic modeling method of numerical analysis in geotechnical engineering based on 3D geologic model

在岩土工程有限元数值模拟中,复杂的地质环境使得建模困难,模型一般都被简化处理。其结果直接影响计算的准确性。借助地质模型能最大程度地表达地质实际的特点,将地质模型和数值模型相结合,提出一种新的岩土工程有限元建模方法——CRM地质模型转化法。其核心思想是将三维地质模型经过特定方式转化为符合有限元网格要求的数值计算模型。具体转化过程为:①根据计算范围对地质模型进行区域切割;②从切割模型提取控制数据进行网格重构;③对重构模型按地层属性自动剖分有限元网格;④将网格数据导入数值分析系统完成建模。通过编程实现与实例验证,这种方法能准确生成复杂模型网格,整体建模速度快,自动化程度高,且能方便地模拟开挖过程,并可为不同的数值分析系统使用,极大地提高了前处理工作的效率。

In numerical simulation of geotechnical engineering, it is necessary to establish model according to complex engineering geological condition. Modeling is so troublesome that numerical model is often simplified in engineering practice. However, the accuracy and reliability of the calculated results are directly influenced by the characteristics of the model. Thus, the researches on modeling method for numerical analysis are necessary. On the other hand, the 3D geologic model can better reflect the actual geological conditions. With regard to such problem, a new and practical modeling method （CRM Geologic Model Transforming Method） of numerical analysis by combining geologic model and numerical model was presented. This method was implemented using the following procedures： ① cutting the 3D geologic model according to numerical calculation region; ② extracting control data from the cut model to reconstruct the model mesh; ③ forming the numerical model automatically by the stratum attribute; ④ importing the model into numerical analysis system and finishing the modeling work. All procedures were carded out rapidly by programming. In the method, the excavation process could be simulated conveniently and the complex model could be used in different numerical systems. It was proved that the method was more accurate and simple and the efficiency of preprocessor was highly improved. Some useful references would be given by the proposed technology to the continuous researches on this subject.