摘要
在滇中香炉山引水隧洞工程区活动断裂部位开展了八个钻孔的水压致裂原地应力测试工作。结果显示工程区应力状态以水平应力为主导,龙蟠-乔后断裂和丽江-剑川断裂部位均为走滑应力状态,鹤庆-洱源断裂西支为走滑应力状态,南段为逆冲应力状态。从应力累积的角度分析,测深范围内三条活动断裂大部分测点实测最大主应力值未超过使断层产生滑动失稳的临界值。地应力测试获得的最大主应力优势方位NNE-NE向与利用该地区震源机制解反演得到的现今构造应力场主压应力方位NEE向存在差异,说明地应力测试结果在一定程度上受到了断层活动性的影响。考虑活动断裂形变和力学属性的多个指标参数,对活动断裂影响程度的Fuzzy-Grey模糊综合评价表明龙蟠-乔后断裂对香炉山隧洞工程的影响较弱,丽江-剑川断裂的影响程度最强,需引起重视。
In-situ stress testing of eight boreholes by hydraulic fracturing was carried out at the active fault zone of Xianglushan Tunnel engineering area of water diversion project in central Yunnan.The results show that the horizontal tectonic stress plays a dominant role in engineering area.The stress regimes in Longpan-Qiaohou Fault and Lijiang-Jianchuan Fault area are of strike-slip faulting.The stress regimes in west branch and south segment of Heqing-Eryuan Fault area are strike-slip and reverse faulting,respectively.From the standpoint of stress accumulation,the measured maximum principal stresses at most test points of the three active faults within the detection range do not exceed the thresholds that cause the slipping instability of the fault.There is a difference between the dominant direction NNE-NE of the measured maximum horizontal principal stresses obtained by in-situ stress test and the NEE direction of the principal compressive stress of the current tectonic stress field obtained from the inversion of focal mechanismin this area,indicating that the measured in-situ stresses have been influenced to a certain extent by fault activities.Taking account of multiple index parameters of active fault deformation and mechanical properties,the Fuzzy-Grey comprehensive evaluation of the influence of active faults shows that the influence of Longpan-Qiaohou fault on tunnel engineering is weak and Lijiang-Jianchuan Fault is the strongest,which should arouse more attention.
作者
付平
张新辉
刘元坤
尹健民
徐春敏
FU Ping;ZHANG Xinhui;LIU Yuankun;YIN Jianmin;XU Chunmin(Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources,Changjiang River Scientific Research Institute,Wuhan,Hubei 430010,China)
出处
《中国地质灾害与防治学报》
CSCD
2020年第5期123-132,共10页
The Chinese Journal of Geological Hazard and Control
基金
国家重点研发计划项目(2016YFC0401803)
国家自然科学基金项目(51879014)。
作者简介
第一作者:付平(1989-),男,河南信阳人,博士,高级工程师,主要从事地应力理论与测试技术、计算岩石力学方面的研究工作,E-mail:fuping@mail.crsri.cn;通讯作者:尹健民(1963-),男,四川南充人,博士,教授级高级工程师,主要从事地质工程和岩土工程方面的研究工作,E-mail:yinjm163@163.com。
