【作者】 刘杰；

【导师】 钟登华；

【作者基本信息】 天津大学 ， 水工结构工程， 2009， 博士

【摘要】 在大型水电工程中,岩体结构是控制坝基坝肩、地下结构和边坡工程等稳定的主要因素之一。对于深埋于坚硬、高应力的岩体内的地下引水发电系统,其区域性地质构造和岩体内随机发育的节理裂隙等构成了地下洞室区域复杂的地质环境,而这些岩体结构面和开挖面组合切割得到的工程岩石块体的失稳将导致洞室围岩的破坏并影响到工程安全。因此,准确分析和预测地下洞室区域的岩石块体信息,包括块体的位置、几何形态、块体与地下结构的相互关系的确定,是大跨度地下洞室设计与施工中需要解决的关键问题之一。本文在水电工程原始地质数据分析的基础上,针对不同类型的地质表达数据研究了确定型建模——地质构造三维建模技术和随机型建模——随机结构面三维网络模拟技术,提出了水电工程岩体结构三维精细建模的理论与方法;在岩体结构三维精细模型的支持下,进行地下洞室曲面块体的识别分析研究。本文主要工作与研究成果如下:1.针对水电工程地质构造特点,基于确定型地质数据,引入水电工程地质构造三维建模方法。研究了面向水电工程地质的三维混合数据结构,地质构造曲面和地质体的NURBS构造技术等,并对岩体结构中的地质构造对象(如地层、断层等)提出了相应的拟合构造和几何建模方法,完成水电工程三维地质构造模型的建立,该模型满足了精度高、数据量小的要求。2.针对裂隙发育的随机性、分组性和分区性特点,基于统计型裂隙数据,引入随机结构面三维网络模拟技术,进行工程区域随机裂隙网络模拟。研究了基于实测数据的模拟裂隙面动态校核技术,以保证模拟结果在采样区与现场情况一致,提高模拟真实性;在三维地质构造模型支持下,研究在地质构造约束区内裂隙面的动态模拟;耦合三维地质构造模型,建立了岩体结构三维精细模型,精细地描述了工程区域复杂的岩体构造系统。3.基于岩体结构三维精细模型,进行地下洞室工程岩石块体的识别分析研究。提出曲面块体的概念和数学定义,并提出曲面块体识别的三大定理——封闭性、完备性和唯一性,为块体识别奠定理论基础;提出了基于无向图的地质结构面网络优化方法,极大地提高了块体识别效率;结合洞室开挖面,设计了约束曲面块体和自由曲面块体的识别功能;研究曲面块体数据结构,并分析其空间几何形态,为进一步的块体稳定性分析提供可靠的地质属性和几何信息。4.依托某水电工程,对上述理论、技术和方法进行了完整、系统的应用研究。建立了该工程区域的三维地质构造模型和岩体结构三维精细模型,并进行地下洞室曲面块体识别和块体几何形态的分析,为进一步的稳定分析和围岩支护提供有价值的定性和定量数据。更多还原

【Abstract】 Rock structure is one of main factors influencing stability problem of dam foundation, dam shoulder, underground structures and slope engineering. In large-scale hydroelectric project, underground water diversion and power generation system is mostly laid deeply into solid rock mass with high geo-stress, and complicate geological environment surrounding the underground structures is made up of regional geological structures, such as fault, weak intercalated layers, and interlayer shear zone, and fissure structures stochastically developing inside rock mass. These geological discontinuities and excavation face of underground structures intersect with each other, and many engineering blocks are cut off. Instability of these blocks will lead to destruction of cave surrounding rock, and then influence project safety. Therefore, accurate analysis and prediction for block information surrounding underground structures, including position, geometrical morphology and relationship with structures, is one of key problems during designing and construction of large span underground cavern. Base on analysis of geological data for hydroelectric project and combing 3D geological modeling with 3D network simulation of discontinuity, theory and method of 3D refined geological modeling for hydroelectric project was present, and, with the help of this model, rapid identification for surface-block of underground structures was studied. The main contents and achievements are as follows:1. Based on determinate geological data and according to geological structures characteristic, method of 3D geological modeling is introduced for hydroelectric project. Hybrid data structure of engineering geology and NURBS construction technology of geological structure for hydroelectric project are studied, and relevant geometry modeling methods are present for different kind of geological object. Then, 3D geological model for hydroelectric project is realized.2. According to fissure development characteristic, randomness, grouping and regionalization, the simulation technology of 3D discontinuity network is introduced to reconstruct stochastic fissure in engineering region. To improve the reality of simulation, the method of dynamic verification for simulated fissure, based on fissure data from field measurement, is researched, and then it is ensured that simulation result will keep the same as field condition in sampling area. With the help of 3D geological structure model, fissure surfaces are dynamically simulated, and 3D refined geological model is rebuilt, which finely descript the complicate geological environment in engineering region.3. Based on 3D refined geological model, the identification method of surface-block in underground structures is studied. Concept of surface-block is presented, and its definition is made. Three theorems, sealability, completeness and uniqueness, are put forward to realize identification of surface-block. To improve identification efficiency, geological structure surface network is optimized with undirected graph, and identification functions of restrict surface block and free surface block are designed.4. The above theories and methods have been applied to a hydroelectric project. 3D geological model and 3D refined geological model are reconstructed, then, identification of surface blocks surrounding underground structures is done, and geometry of these blocks are analyzed, which supplies many useful qualitative and quantitative data for the following stability analysis and surrounding rock support.更多还原