【作者】 李新星；

【导师】 朱合华；

【作者基本信息】 同济大学 ， 结构工程， 2008， 博士

【摘要】 随着地下空间的开发利用与岩土工程的数字化信息化技术的发展,为了对地下工程的建设和发展服务,用数字化方式将原始复杂地质条件和地层信息进行直观表现,来构建数字地下空间与工程(DUSE)系统,是目前正在研究的课题。数值分析方法作为岩土工程领域的一种重要模拟分析手段,将其计算功能集成到数字化系统是大势所趋。如何对两种系统进行互为补充、扬长避短、高效便捷的集成是这一新兴研究领域的一大难题。鉴于此,本文以DUSE系统为研究基础,从数字建模和数值分析两个角度出发,提出实现数字—数值一体化的思想,并以此为主线,对其实现一体化的集成模式、集成内容、组织结构、实施框架等内容进行了全面、系统的研究,同时对其实现一体化的核心技术作了重点研究与实现。主要内容如下:(1)本文首先对正在研究的数字地下空间与工程信息系统(DUSES)作了全面介绍,对整个系统的框架结构设计和功能模块的研制进行分析论述。在确定DUSES基本功能的基础上,对其数据及管理功能、三维建模功能、可视化功能、空间分析功能和专业应用功能等内容进行了详细论述。(2)对地下工程有限元数值分析系统的前处理技术进行了研究。根据有限元数值分析方法以及系统前处理的流程结构,对系统中的数据及其处理方式和有限元建模规则与方法进行了详细研究,并探讨了在地下工程中复杂计算模型的有限元网格生成模式。(3)提出基于DUSE的数字—数值一体化的概念,并决定采用一种复合式体系结构(嵌入式+松散式)的集成方式来实现其一体化。从数据、功能和技术三方面来研究集成内容,分别从DUSE系统和数值分析系统的角度构建系统一体化的组织结构,最终制定出严密的一体化系统整体实施框架及其执行步骤。(4)对数字—数值一体化中的核心技术进行研究,针对两种模型的差异性,通过依次运用区域切割技术、表面模型重构技术、有限元网格自动生成技术,提出一种CRM地质模型转化法来实现模型一体化。在区域切割算法中,采用多边形平面与三角形平面的相交计算加以实现,提高了整体切割计算的效率,避免了冗余数据的产生,能够方便的模拟岩土工程中的开挖施工过程,并可使地质模型具有一次建模多次使用的功能。基于Delaunay编制了表面模型重构算法和三维空间平面的有限元三角网格自动剖分算法,提出并采用“多TIN域”法来自动生成地质表面模型的有限元网格,避免了较复杂的任意域网格自动剖分算法以及手动寻求封闭区域、边界逐一离散等人机交互现象。在有限元体网格生成过程中,提出“单空间域”和“多空间域”的概念,以及按不同地层属性进行分块的思想,避免了复杂的手动构建体网格自动剖分区域的过程及其封闭性检验和人机交互式的几何检查等技术难题。(5)对数字—数值一体化系统平台进行总体设计,以ACCESS为数据库支撑,利用VC++和OpenGL从底层开发三维可视化图形平台以及有限元数值分析功能模块,实现了数据一体化和功能一体化的集成内容,最后分析了整个一体化系统所存在的不足。(6)结合上海世博变电站基坑开挖工程,应用本文提出的基于DUSE的数字—数值一体化建模方法和系统平台,对其进行三维有限元数值计算与分析,以展示一体化系统的执行过程和优越性。更多还原

【Abstract】 With the exploitation of underground space and the development of information visualization in geotechnical engineering, the primitive complex geological condition and strata information are shown in digitized way in order to serve for the construction of underground engineering. Aiming at the situation, the Digital Underground Space and Engineering (DUSE) is established and it is in process of research. Numerical analysis is an important simulation method in the field of geotechnical engineering. However, the lack of visualization model is the difficulty to implement mechanical analysis and current numerical simulations are difficult in geological modeling. It is ultimately necessary to integrate calculation function into the digitalization system and it is a great challenge to how to perfectly implement it.In full consideration of the characteristics of digital modeling and numerical analysis, a new idea is presented, which realizes the integration of digitalization and numerical analysis based on the DUSE system. Taking the thinking as masterstroke, this thesis carries through a completely, systemically research on the key techniques of integration. The primary contents are as follows:1. DUSE system is roundly introduced, and its framework and functional module are analyzed. The main functions, including data management, 3D modeling, visualization, spatial analysis and special application, are discussed respectively.2. The preprocessing of FEM numerical analysis is analyzed. According to the flowchart of finite element analysis, the data, processing mode, modeling regulation and method are studied in detail. The mesh generation method of the complex model in the underground engineering is explored.3. The thought of the integration of digitalization and numerical analysis based on DUSES is presented. The coupling mode is determined to adopt a new composite structure of loose coupling and embedded coupling. And the coupling contents are discussed from three aspects of data, function and technique. The organizational structure is built from two aspects of DUSE system and numerical analysis system. The implementation frame and procedure of the integration system is established.4. The key technique of the integration is investigated. In the view of two kinds of different models, a method, called CRM geologic model transforming method, is presented to realize the model coupling by using the techniques of region cutting, model reconstruction and automatic generation of FEM mesh sequentially. The algorithm of region cutting is fulfilled with the intersection calculation of plane and polygon. It is highly efficient and can avoid to product the redundant data. By region cutting, the construction process can be simulated conveniently and the geologic model can be used repeatedly. Based on the Delaunay triangulation, the algorithm of the surface model reconstruction and FEM triangle meshing in space plane are performed. A multiple TIN region method is presented to generate automatically FEM mesh of the geologic surface model. Then, some man-machine interaction operations can be avoided, such as seeking manually the closed region and discretizing the boundaries one by one. In the process of FEM solid meshing, the conceptions of Single Space Region (SSR) and Multiple Space Region (MSR) are presented, and the thought of the blocking by strata attribute is applied in the MSR method. The manual construction for the SSR and the geometry inspection can be avoided before solid meshing. The efficiency of the whole modeling is improved thoroughly.5. A platform of the integration system is exploited. Using ACCESS for data storage and OpenGL for image processing, the 3D visualization interface and the FEM analysis module are exploited by VC++. So the data coupling and the function coupling are realized. Then, several defects of the integration system are indicated.6. The new analysis method presented in this thesis are applied into a real project of 2010 Expo power station in Shanghai. Excavation process of the foundation is simulated and analyzed. The procedure and the superiority of the integration system are shown sufficiently.更多还原