差应变法地应力测量——以汶川地震断裂带科学钻探WFSD-1钻孔为例  

IN-SITU STRESS MEASUREMENT BY DIFFERENTIAL STRAIN ANALYSIS METHOD IN WFSD-1

作　　者：彭华[1,2] 马秀敏[1,2] 姜景捷[1,2] 

机构地区：[1]国土资源部新构造运动与地质灾害重点实验室,北京100081 [2]中国地质科学院地质力学研究所,北京100081

出　　处：《地质力学学报》2011年第3期249-261,共13页Journal of Geomechanics

基　　金：科技部"汶川地震断裂带科学钻探"项目和地调项目(编号:1212010916064)联合资助

摘　　要：岩心差应变分析法是汶川地震断层科学钻探(WFSD)项目地应力测量的主要手段之一,该技术通过高压容器对取之于钻孔不同深度的实验样品施加围压,观察先前由于失去地层应力而膨胀产生的裂纹重新闭合,并通过裂纹闭合过程差应变曲线分析,确定主应力大小和方向。WFSD-1孔12个岩心样品的DSA测试结果表明:断层上下盘的应力状态有明显差异,区域地应力不仅随深度增加,还与地质结构和岩石的物理性质等因素有关。Core differential strain analysis method is one of the primary means of in-situ stress measurement in WFSD.Through the pressure vessel,the experimental samples taken from different depths are pressured.And it is observed that the produced cracks are re-closed due to the previously loss stratum stress.The technology is that the size and direction of principal stress are determined by differential stain analysis in the process of crack closure.This article describes the principle and data processing method of in-situ stress measurement by differential strain analysis（DSA） in WFSD-1.And the stress profile is established with depth in the hole.Test results show that the stress states of the upper and lower plate in the Yingxiu-Beichuan fault are significant differences.Regional in-situ stress not only increases with depth,but also concerns with the geological structure,rock physical properties and other factors.

关 键 词：汶川地震断裂带科学钻探 映秀—北川断层 差应变分析法(DSA) 地应力测量 滑动准则 

分 类 号：P315[天文地球—地震学]