断层影响带的发育规律及其力学成因  

The development law and mechanical causes of fault influenced zone

作　　者：雷光伟 杨春和[1,2] 王贵宾[2] 陈世万 魏翔[1] 霍亮[1] 

机构地区：[1]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400044 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071

出　　处：《岩石力学与工程学报》2016年第2期231-241,共11页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金青年基金项目(40802078)~~

摘　　要：断层影响带的发育规律和范围是高放废物处置库选址和设计的重点内容之一。采用现场测量和图表分析等方法,研究断层两侧节理平均迹长和中点面密度与距断层距离之间的变化规律,结果表明:(1)平均迹长随断层距离增加而变大,中点面密度随断层距离增加而变小,且变化特征均符合负指数函数形式;当距离超过断层影响带宽度d_0,节理平均迹长和中点面密度均稳定在某一值附近波动。据此将断层影响带分为严重破坏区Ⅰ和影响区Ⅱ两个区域;(2)断层类型不同,断层影响带大小和发育规律存在显著差异,其中,正断层最小,平移断层次之,逆断层最大;平移断层两盘的影响带近似呈对称分布,而正断层和逆断层呈上盘宽、下盘窄的不对称分布。此外,断层影响带宽度与断层长度之间服从幂函数形式。分析认为:呈现上述变化特征和发育规律的原因主要是岩性和形成断层时的力学机制不同。研究结果对岩体结构面均质区划分、地下水分布和处置库设计等具有重要的工程指导意义。Fault influenced zone is one of the key factors in site selection and design for high-level radioactive waste repository. Field survey and chart analysis were used to obtain the relationship between the fault distance and mean length of traces,the midpoint density of both sides of fault. When the distance increases,the mean trace length increases and the midpoint density decreases. The correlations obey a negative exponential function. When the distance exceeds the width of the fault influenced zone,the mean trace length and the midpoint density fluctuate at a certain value. Accordingly,both sides of the fault can be divided into two regions：serious influenced zone I and influenced zone II. The width of the maximum influenced zone and the distribution are markedly different among different fault types,the one of the normal fault is the smallest,the one of the strike-slip fault is the second,and the one of the reverse fault is the largest. Meanwhile,the influenced zone of the strike-slip fault shows a symmetrical distribution,and the normal and reverse faults show asymmetrical distribution. The width of fault influenced zone and the length of fault obey a power function approximatively.

关 键 词：岩石力学 断层影响带 节理 中点面密度 平均迹长 构造应力 

分 类 号：TU45[建筑科学—岩土工程]