【摘要】 探究断层泥力学行为是研究断裂带工程地质效应的基础,以延安神道沟断裂带断层泥为对象,借助颗粒分析、X射线衍射等微观测试手段研究了3种颜色断层泥的组构特征,并通过环剪试验分析了不同含水率条件下重塑断层泥的力学行为。研究结果表明:单峰型粒径曲线的断层泥级配明显优于双峰型,石英、云母和长石为主要的非黏土矿物,黏土矿物则以伊利石和高岭石为主,赤铁矿与绿泥石的相对含量是造成断层泥颜色差异的主要原因;受含水率和粗颗粒含量的影响,断层泥应变软化特征显著,应变软化随着含水率增大呈现先增强后减弱的变化规律,当含水率小于塑限含水率时,应变软化特征则随着粗颗粒含量升高而趋弱;内摩擦角是影响应变软化特征的主要力学指标,峰值内摩擦角和残余内摩擦角均与含水率呈负相关;矿物含量影响内摩擦角的变化,在5%和10%含水率条件下,内摩擦角随非黏土矿物含量的升高而增大。更多还原

【Abstract】 Exploring the mechanical behavior of fault gouge is the basis of studying the engineering geology effects of fault zone. Taking the gouges of Shendaogou Fault in Yan’an as an object,the fabric characteristics of three color fault gouges are studied with particle analysis and X-ray diffraction( XRD). In addition,the mechanical behavior of remolded fault gouges under different water contents are analyzed with ring shear test. The results show that the gradation curve with single peak of fault gouge particle is significantly better than that with double-peaks. Quartz,mica and feldspar are the main non-clay minerals,while illite and kaolinite are the main clay minerals. The color difference of fault gouge is brought by the relative content of hematite and chloriter. The strain softening characteristics of fault gouge are mainly affected by water content and coarse particle content. The strain softening is first strengthened and then weakened with the increase of water content. When the water content is less than the plastic limit,the strain softening characteristics weaken with the increase of coarse particle content. Internal friction angle( φ) is the main mechanical parameter affecting strain softening characteristics. Peak internal friction angle and residual internal friction angle are negatively correlated with water content. The variation of φ is influenced by the mineral composition,which indicates that φ increases with the increase of non-clay mineral under 5% and 10%water content.更多还原