【作者】 殷黎明；

【导师】 杨春和；

【作者基本信息】 中国科学院研究生院（武汉岩土力学研究所） ， 岩土工程， 2008， 博士

【摘要】 在花岗岩这类硬岩中处置高放废物,遍布花岗岩体中的节理裂隙是控制处置的关键因素,连通的裂隙网络是核素迁移的主要通道。因此对节理裂隙的水力、力学特性进行深入的研究是十分必要的。本文以中国高放废物深地质处置甘肃北山预选区候选场址评价为研究背景,以北山采石场区域中分布的节理为研究对象,运用现场调查、钻孔试验、统计分析、室内试验以及数值模拟等多种手段对节理面的分布特征、表面形态特征、单节理面力学特性以及节理网络渗流应力的耦合特性展开了研究。通过对中国高放废物处置库甘肃北山预选区岌岌采石场的岩体露头进行节理调查,统计了采石场区域节理分布的各项基本特征,为进一步研究节理面的各项物理力学特征建立了分组依据。针对节理分组特征,在采石场区域选取典型节理面,运用基于Barton直边法的快速几何测量法,对现场大尺寸节理面表面形态进行了测量。分析了该区域节理面表面形态的尺寸效应、各向异性等特性。并且分析了剖面曲线的参数特征。天然节理面中往往既包含有周期长、幅值大的起伏度分量和周期短、随机性的粗糙度分量。两者对节理面的影响机理是不同的,不考虑两者的区别而笼统地分析显然是存在缺陷的。本文将节理面的表面形态曲线看作是一离散的时间序列,引用频谱分析法实现了两者的分离,讨论了分离阙值频率的选择,并且分析了不同分量的参数特征。试验方法是研究节理力学特征最直接有效的方法,对现场选取的150×150×150mm的标准中间含平行节理试样进行了法向压缩试验和直接剪切试验,研究了节理面的变形特征与强度特征,并且对试样的节理面表面形态特征进行了分析。研究了节理面不同分量对节理面力学特性的影响规律。针对现场某深钻孔进行了地应力测量与高压压水试验,分析了现场岩体渗透特性,应用离散元程序UDEC对基于上述调查统计的裂隙网络进行了应力场与渗流场的耦合分析。更多还原

【Abstract】 Fractures in granite rock mass always provide the major channels for nuclide to escape to the biosphere. When planed to dispose HLW (high level radioactive waste) into these kinds of hard rock mass, joints are one of the most important factors to be considered carefully. This paper based on the site investigation of Beishan Area, Gansu province, the preselected area of Chinese High Level Radioactive Waste. In-situ investigation, borehole water inflow test, statistics analysis, lab test and numerical simulation are done to better understand the distribution trends, joint surface characteristics, joint mechanics and the coupled water flow in rock mass.More than 500 outcrops are investigated in one of the preselected area-the quarry area, geological and statistical methods are used to study about 12000 joints scattered in these outcrops. Some basic characteristics such as dip, dip direction, space, aperture, mean trace length etc are obtained and these joints are subdivided into 4 groups. This work is the foundation of further study of fracture’s another property.It is well known that nature fracture is always undulated and rough, the characteristics of fracture surface is one of the most important factors to affect its action. It is necessary to research about these characteristics especially in-situ joint. A geometry approach based on Barton’straight edge method is introduced to these investigation, plenty of large scale surface configuration profile curves are obtained. It shows that scale effect, anisotropy are prominent for these profile curves, and JRC (joint roughness coefficient) of tensile fracture is always 1.24 times larger than that of shear joint.Undulate part and rough part are two basic components of the nature fracture. Undulate part is always characterised with large undulate breadth and long undulate cycle, and rough part is defined on the contrary way. These different properties lead to absolutely different effects on joint’s mechanics and hydro-mechanics. It is an interesting work to separate these different parts from the original profile curve. Frequency analysis is used to make it done. In this method profile curve can be seemed as a discrete time series and different parameters of different parts are obtained. Another important aspect is the determination of the valve separate frequency which is also discussed in this paper.Lab test is the most direct and effective ways to study joint’s properties. But how to get these test samples with nature joints is not an easy work. Under the help of special rock product machines some rock samples with standard scale of 150×150×150mm are obtained and well-conserved for lab test. Normal compress test and direct shear test are performed on these samples, and before these tests the profile curves of the fracture located in the mid of sample are analysed. Rules of effect of surface configuration on fracture’mechanics properties are obtained through these tests. Hydraulic method is used to measure geo-stress, and high water pressure inflow test is carried out in a 500m deep borehole. UDEC is used to analyse the couple effect of H-M on a fracture net, and this net is created based on the former investigation.更多还原