【作者】 孙少锐；

【导师】 吴继敏；

【作者基本信息】 河海大学 ， 岩土工程， 2004， 博士

【摘要】 裂隙岩体中的超欠挖问题是一个极其复杂的工程地质问题，对超欠挖预测和评价方法的研究是本文的主要研究内容。归纳如下： (1) 对结构面网络模拟技术的基本原理、基本方法以及现状进行概述，在充分考虑岩体受力的力学机理基础上，结合野外测得的结构面特征参数及现场地应力分布特征，提出一种基于地质力学机理的结构面网络模拟技术，并把该技术运用到地下洞室的超挖预测中。通过工程实例验证结果的合理性，结果表明：考虑岩体受力机理的结构面网络模拟技术能充分反映岩体结构面的特征、合理预测洞室中的超挖问题。块体理论是研究洞室超欠挖的重要工具，它是从拓扑几何学的角度来研究洞室中的关键块体，但关键块体与超挖块体之间存在区别，文中对超挖块体和关键块体之间的关系进行分析研究，应用块体理论和结构面网络模拟技术相结合的方法预测了洞室超挖块体的大小。 (2) 岩体的地质特征和地质组成是影响洞室围岩超欠挖的主要因素之一。论文旨在从岩体的破坏机理出发，对裂隙岩体开挖后的洞室周边分数维进行研究，提出了裂隙岩体洞室开挖周边的广义分数维模型，并且对不同影响参数与洞室周边分数维之间的关系进行分析，从分形理论的角度建立洞室周边广义分数维与洞室超挖之间的关系，从而建立了以岩体破裂机理为基础的超欠挖与广义分数维之间的关系。爆破开挖是影响洞室超欠挖的另一个重要因素。迄今为止，国内有关爆破开挖对超欠挖影响的研究尚未见报道，论文从洞室周边破坏机理的角度出发来研究爆破产生的洞室周边界形状，并建立洞室应力、应变与超欠挖之间的关系，完善了洞室超欠挖与分数维及洞室动态破坏之间的关系，同时还研究了超欠挖对围岩稳定性的影响。 (3) 论文提出了基于地质统计模型的小波神经网络对地下洞室超挖块体进行预测的基本方法。首先，简述了超挖预测的两个基本理论，即地质统计模型理论和小波神经网络理论；其次，根据几个基本理论介绍了超挖预测的整个程序设计过程，并编制了相应的计算程序。其中，地质统计模型采用概率论与数理统计的基本理论、小波神经网络是采用小波基作为神经网络激励函数的前馈型网络；最后，从野外地质调查着手，结合某一抽水蓄能电站的实测地质资料，应用基本理论对几个洞室超挖块体的大小进行预测，为地下洞室防止或减少超挖提供理论依据。 (4) 正确评价岩体的质量，进行围岩分类，对研究岩体质量与洞室超欠挖之间的关系及分析和预测洞室超欠挖具有重要的意义。论文对洞室围岩的RMR分类和Q分类与超欠挖之间的关系进行详细的研究，研究不同开挖洞径与洞室超欠挖之间的关系，并由此建立了RMR分类和Q分类之间的关系，得出围岩的RMR分类和Q分类与洞室超欠挖呈线性关系或对数线性关系。根据超欠挖建立起来的RMR分类和Q分类之间的关系比较符合工程实际。论文还研究了超欠挖与围岩分类及洞径之间的复相关关系。中文摘要 (5)图像处理技术在很多工程领域中得到推广应用，在洞室超欠挖评价中的应用是图像处理技术在地质及岩土工程领域的推广。其基本原理是:对野外摄取的洞室的基本剖面形状进行几何校正，然后应用图像学中的投影重建方法使图像不失真，对修正后的图像实行灰度图像的开操作和闭操作运算，得到洞室的基本形状，然后用图像学中的边界提取技术提取洞室的周边界，与洞室的设计形状对比分析，得到洞室在该断面上的超欠挖方量，然后对其它断面采用同样的技术就可评价某一段或整个洞室的超欠挖数量，从定量的角度解决了工程中的超欠挖评价问题。关键词:超欠挖;预测;结构面特征;结构面网络模拟;块体理论;广义分数维;爆破开 挖;周边破坏;地质统计模型;小波神经网络;围岩分类;图像处理;开操作和 闭操作更多还原

【Abstract】 It is a complex engineering geology problem for forecasting overbreak as well as underbreak in jointed rock mass openings. The research on forecasting and evaluation of overbreak as well as underbreak is the mainly contents in this paper. Mainly contents includes: . . (1) The basic principal, basic method and general situation of discontinuity mapping are summarized in this paper. Combined geodesic discontinuity parameters in the fields and distribution of ground stress state in situ, one discontinuity mapping method based on geological mechanics mechanism is put forward. The technology is applied in forecasting and evaluation of overbreak as well as underbreak in jointed rock mass openings. The veracity of result will be tested by an engineering example. The result shows that discontinuity mapping considering geological mechanics mechanism can reflect discontinuity characters and forecast properly overbreak in jointed rock masses openings. The key block theory is an important tool to study overbreak as well as underbreak in the openings because it researches key block from the angle of topology. However, the key block is different from overbreak block. The relation between overbreak block and key block is researched in this paper. The method for forecasting of overbreak block by using key block theory combined discontinuity mapping is applied.(2) The geological characters of rock mass and geological constitution is the mainly factors of affecting overbreak as well as underbreak in the openings. From the mechanism of rock rupture, the fractal dimension of openings perimeter is researched in jointed rock mass in this paper. The generalized fractal dimension model of openings perimeter in jointed rock mass is put forward. The relation between effecting parameters and generalized fractal dimension of openings perimeter is analyzed. According to the fractal theory, the relation between overbreak as well as underbreak and generalized fractal dimension of openings perimeter is built. Based on geological mechanics mechanism, the relation between overbreak as well as underbreak and generalized fractal dimension is built. The blasting excavation ways are the other factor of affecting overbreak as well as underbreak in the openings. So far, the research about the effect of blasting excavation to overbreak as well as underbreak is not be reported in the domestic. The openings perimeter shape that is be affecte4 by blasting is researched from the angle of rock rupture. The relations between overbreak as well as underbreak and stress as well as strain are researched. The relations among overbreak as well as underbreak and fractals and dynamic rupture of openings perimeter are consummated. At the same time, the affecting of overbreak as well as underbreak to surrounding rock stability is researched.(3) The forecasting methods of overbreak block in the openings based on wavelet neural network of geological statistics model is put forward. Firstly, two basic theories, including theory of geological statistics model and theory of wavelet neural network, are introduced. Secondly, according to two theories, the proceeding of program designing is introduced and the calculation program is designed. In these, geological statistics model relates to the probability and statistics; wavelet neural network relates to sigmoid function used by wavelet neural network. Lastly, according to geological datum in a pump-storage hydroplant,application of two theories is in forecasting overbeak of several openings. The forecasting result provides a basis for avoiding overbreak or decreasing overbreak.(4) It is important for evaluating rock mass quality correctly and classifying surrounding rock, analyzing and forecasting overbreak as well as underbreak in the openings, researching relation between rock mass quality and overbreak as well as underbreak. Both the relation between classification of Q and overbreak as well as underbreak and the relation classification of RMR and overbreak as well as underbreak are researched in this paper. The relation betw更多还原