雅鲁藏布江断裂带东段现今地应力测量与断层活动性分析  

Present in situ stress measurement in the eastern segment of Yarlung Zangbo River fault and fault activity analysis

作　　者：孙炜锋[1] 黄火林 孙东生[1] 孟文[1] 陈群策[1] SUN Wei-feng;HUANG Huo-lin;SUN Dong-sheng;MENG Wen;CHEN Qun-ce(Technology Innovation Center for In-situ Stress,Ministry of Nature Resources,Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;PowerChina Huadong Engineering Corporation Limited,Hangzhou,Zhejiang 311122,China)

机构地区：[1]中国地质科学院地质力学研究所自然资源部地应力工程技术创新中心,北京100081 [2]中国电建集团华东勘察设计研究院有限公司,浙江杭州311122

出　　处：《岩土力学》2024年第4期1129-1141,共13页Rock and Soil Mechanics

基　　金：中国地质调查局地质调查项目(No.DD20242395,No.DD20190319)。

摘　　要：为获取位于雅鲁藏布江断裂带东段加查县新建水电站工程场区的地应力状态,探讨雅鲁藏布江断裂带东段活动性,采用自主研发的新一代水压致裂地应力测试技术,实测获取了工程场区的地应力状态,并在收集雅鲁藏布江断裂带沿线地应力数据基础上,结合摩尔-库仑破裂准则,对其断层活动性进行了探讨。结果表明:(1)在工程厂区内122.75~418.75 m深度,实测最大水平主应力SH介于6.07~37.62MPa之间,最小水平主应力Sh介于3.13~20.33MPa之间,最大水平主应力优势方向为北北东向;(2)主应力关系总体表现为SH>Sh>Sv(Sv为垂向主应力),应力结构有利于逆断层的孕育和活动;(3)实测及收集的大部分数据应力莫尔圆与摩擦系数为0.6的破坏临界线相交,表明整体上雅鲁藏布江断裂带东段发生滑动失稳的风险较高,其中西侧贡嘎至朗县一带风险高于东侧林芝地区。In order to determine the in situ stress state of the newly built hydropower station project in Jiacha county,and understand the activity of the eastern segment of the Yarlung Zangbo River fault zone,we obtained the in situ stress data in the engineering field by using the self-developed deep-hole stress measuring equipment based on the hydraulic fracturing method.We analyzed the fault activity by employing the Mohr-Coulomb failure criterion and the collected in situ stress data along the eastern segment of the Yarlung Zangbo River fault zone.The results showed that:(1)The magnitudes of the maximum horizontal stress SH ranged from 6.07 MPa to 37.62 MPa,the values of the minimum horizontal stress Sh were from 3.13 MPa to 20.33 MPa at the depth from 122.75 m to 418.75 m,and the dominant direction of the measured maximum horizontal principal stress was nearly NNE.(2)The stress regime was mainly characterized by SH>Sh>Sv(Sv is the vertical principal stress),which was prone to reverse faulting.(3)Most of the measured and collected Mohr stress circles intersected the failure threshold line with friction coefficient equal to 0.6,which indicated that the eastern segment of the Yarlung Zangbo River fault zone was in a high level of fault slip instability.Furthermore,the fault slip risk of the west section from Gongga to Langxian was higher than that of the east section near Linzhi along the eastern segment of the Yarlung Zangbo River fault zone.

关 键 词：地应力 水压致裂法 断层活动性 雅鲁藏布江断裂 青藏高原 

分 类 号：TU42[建筑科学—岩土工程]