基于断层擦痕侧伏角公式的构造应力张量反演  

Back analysis of tectonic stress tensor based on the formula for calculating pitch direction of fault slip data

作　　者：何书[1] 赵奎[2] 朱忠[1] 吴开兴[1] 

机构地区：[1]江西理工大学资源与环境工程学院,江西赣州341000 [2]江西理工大学工程研究院,江西赣州341000

出　　处：《岩土力学》2012年第11期3414-3418,共5页Rock and Soil Mechanics

基　　金：江西省青年科学基金资助项目(No.2010GQC0049);国家重点基础研究发展计划资助项目(No.2011cb411913);国家自然科学基金项目(No.51064010);国家科技支撑计划项目子课题(No.2008BAB32B03)

摘　　要：利用Aleksandrowski推导的断层擦痕侧伏角公式,提出了一种改进的构造应力张量反演法。根据不同应力比值下构造应力与断层擦痕侧伏角的关系,利用最小二乘法,详细推导了构造应力张量的反演方法,最后利用Matlab软件编制程序实现了该计算过程。在此基础上,现场调查了江西武山铜矿北矿带的断层滑动数据,利用上述改进方法反演了该地区的构造应力张量方向特征。将上述反演结果与由震源机制解获得的最新构造应力场结果进行对比分析,并结合研究区断层的展布特征及所在的地质构造背景,获得了该地区自晚侏罗世以来的构造应力场特征,表明该地区构造应力场具有一定的稳定性。改进后的构造应力张量求解过程及工程应用表明,将Aleksandrowski的图示法和Etchecopar等的反演法结合起来反演构造应力张量,是对已有方法的改进,具有更加简单、实现容易等特点,计算结果比较符合实际。Based on the formula deduced by Aleksandrowski for calculating pitch direction of fault slip data,an improved method for determination of tectonic stress tensor was put forward.A method for back analysis of tectonic stress field was deduced by least square method based on the relation between tectonic stress with pitch direction of fault slip data in different stress ratio values.At last,the calculating process was deduced by Matlab program.The fault slip data were obtained in the Wushan mining region,Jiangxi province.On this basis,by the improved method of inversion of fault slip data,the parameters of tectonic stress tensor in mine region were determined.The tectonic stress field in this area since Late Jurassic was obtained,by comparing the faults with the average stress field of the region obtained from focal mechanism solutions and studying distribution of the strike-slip faults and the tectonic setting of this area.It is indicated that the tectonic stress field in this area has better stability since Late Jurassic.The progress of solving tectonic stress tensor and the application of the improved method show that,comparing with the graphical instrument method put forward by Aleksandrowski and the method for back analysis by Etchecopar,the method is simple and more feasible,and the focal mechanism solution is reasonable.

关 键 词：断层擦痕 侧伏角 反演 武山铜矿 构造应力张量 

分 类 号：P554[天文地球—构造地质学]