节理岩体结构面空间表征及其模型优化

发布时间：2018-10-26 21:46

【摘要】：岩体是由岩块和分离切割岩块的结构面组成的岩体结构。岩体结构面具有大小不一、产状不同、形态各异等特点,因而岩体呈现出不连续、非均质及各向异性等力学性质。大量的工程实践可以表明在隧道洞室开挖过程中,结构面的几何和物理特性对岩体的变形和破坏起着关键性的控制作用,对工程岩体的稳定性有重要影响。工程岩体的稳定性分析是一个非常重要的实际问题,如地下洞室的开挖,修建隧道,开凿运河渠道、在山区修筑道路、桥梁、高峡建坝、深谷修库以及露天采矿等,这些工程都需要分析岩体的稳定性。随着计算机的发展,数值模拟方法在分析岩体的稳定性方面具有独特的优势。如何建立岩体结构的分析模型,在获取的大量的结构面信息基础上进行全面的表征和模拟,并把将结构面的物理参数的影响因素考虑在内,建立更加准确的岩体隧道三维结构面空间模型,并合理分析结构面与开挖面间的相互作用,对影响岩体稳定性的关键块体进行搜索,最终将计算结果进行真三维显示,是隧道工程开挖过程中稳定性研究的关键性问题。本文在阅读大量文献,总结结构面研究方法和岩体稳定性分析方法的基础上,基于数字摄影测量方法,应用狄洛尼三角剖分方法进行了结构面表面的三维网格重建；利用建立的表面三角网格模型,进行了结构面张开度的模拟,优化了结构面的圆盘模型；提出了三维粗糙度表征的新方法—(surface area ratio, SAR);并在验证粗糙度系数的基础上,进行了结构面里力学参数的经验估算,主要开展如下工作：首先,应用数字摄影测量系统进行结构面的采集,通过结构面出露部分的表面形态来反映整个结构面的三维空间形态,应用ShapeMetriX3D系统进行出露部分点数据的获取。在此基础上应用Delaunay三角剖分方法进行结构面表面的重建,实现了通过三维三角网格来反映结构面的表面形态。其次,考虑二维粗糙度在表征结构面粗糙性的不足,在结构面表面三维重建的基础上,提出了比表面积法(surface area ratio, SAR),通过结构面的网格面积与拟合面积之间的比值来反映粗糙度大大小。根据现场结构面的测量,应用修正直边法进行了粗糙度系数的计算,针对JRC与SAR做了相关性分析。再次,根据重建的结构面,计算张开度的平均值,采用等效张开度作为单一结构面的张开度进行计算机模拟。应用Barton公式进行了结构面力学参数的经验估算。最后,结合具体的工程实例,采用ShapeMetriX3D系统现场采集结构面的信息,通过结构面网络模拟方法表征结构面的真实信息,建立岩体隧道三维结构面模型,应用程序搜索关键块体,分析岩体的稳定性,并与实际工程进行对比分析,检验程序的有效性,并对结果进行显示。
[Abstract]:Rock mass is a rock mass structure composed of rock blocks and the structural planes of separate cut rock blocks. The rock mass structure mask has the characteristics of different size, different occurrence and different shape, so the rock mass presents discontinuous, heterogeneous and anisotropic mechanical properties. A large number of engineering practices can show that the geometric and physical characteristics of the structural plane play a key role in controlling the deformation and failure of rock mass and have an important effect on the stability of engineering rock mass during the excavation of tunnel cavern. The stability analysis of engineering rock mass is a very important practical problem, such as the excavation of underground caverns, the construction of tunnels, the opening of canal channels, the construction of roads, bridges, dams in Gaoxia, the repair of deep valleys and open pit mining, etc. These projects need to analyze the stability of rock mass. With the development of computer, numerical simulation method has a unique advantage in analyzing the stability of rock mass. How to set up the analysis model of rock mass structure, on the basis of obtaining a large amount of information of structural plane, to carry on the comprehensive representation and simulation, and to take into account the influence factors of the physical parameters of the structural plane. A more accurate three-dimensional structural plane space model of rock mass tunnel is established, and the interaction between structural plane and excavated surface is reasonably analyzed, and the key blocks that affect the stability of rock mass are searched. It is a key problem in the stability study of tunnel excavation. On the basis of reading a lot of literature, summarizing the methods of structural plane research and rock mass stability analysis, based on the digital photogrammetry method, this paper uses the Dilloni triangulation method to reconstruct the three-dimensional mesh of the structural plane surface. Using the established surface triangular mesh model, the structural surface opening degree is simulated, and the disk model of the structure surface is optimized. A new method of 3D roughness characterization, (surface area ratio, SAR);, is proposed. On the basis of verifying the roughness coefficient, the empirical estimation of the mechanical parameters in the structure plane is carried out. The main work is as follows: firstly, the acquisition of the structural plane is carried out by using the digital photogrammetry system. The surface morphology of the exposed part of the structure surface is used to reflect the 3D spatial form of the whole structure surface, and the data of the exposed part are obtained by using ShapeMetriX3D system. On this basis, Delaunay triangulation method is applied to reconstruct the surface of the structure surface, and the surface shape of the structural plane is reflected by the three-dimensional triangular mesh. Secondly, considering the deficiency of two-dimensional roughness in characterizing the roughness of structural surface, a specific surface area method (surface area ratio, SAR),) is proposed on the basis of 3D reconstruction of structural surface. The large roughness is reflected by the ratio of the mesh area to the fitting area of the structural surface. According to the measurement of the field structure surface, the roughness coefficient is calculated by the modified straight edge method, and the correlation between JRC and SAR is analyzed. Thirdly, according to the reconstructed structure surface, the average opening degree is calculated, and the equivalent opening degree is used as the opening degree of a single structural plane for computer simulation. The Barton formula is used to estimate the mechanical parameters of the structural plane. Finally, combining with the concrete engineering example, using ShapeMetriX3D system to collect the information of the structural plane on the spot, the real information of the structural plane is represented by the network simulation method of the structural plane, the 3D structural plane model of the rock mass tunnel is established, and the key blocks are searched by the application program. The stability of rock mass is analyzed, and compared with the actual engineering, the validity of the program is verified and the results are shown.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU45

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