摘要
针对秦岭输水隧洞大埋深、高地应力容易引起岩爆、大变形等工程灾害的问题,为预防和减轻地应力分布和变化对施工进程和人员设备安全的不利影响,对秦岭隧洞隧址区典型位置(越岭段、岭南、岭北)分别进行了水压致裂法应力测试,并对无断层段和含断层段进行了三维地应力场反演分析,研究了秦岭隧洞初始地应力场特征及规律。结果表明:秦岭隧洞地应力表现出较强的水平构造应力作用,岭南岭北勘探试验最大主应力为25.4～27.7 MPa,垂直孔测得最大水平主应力方向稳定在近EW向。数值模拟可以较好地反演分析秦岭输水隧洞的地应力分布,无断层段隧洞最大主应力多为10～45 MPa,最小主应力多为0～15 MPa;含断层段隧洞主轴最大水平主应力值较高,变化范围为20.46～71.94 MPa,最高达71.94 MPa。由于断层破碎带的存在,附近区域会出现剧烈的应力变化,断层带以内应力值显著减小,而断层带两侧出现应力集中,局部应力值升高。
Aiming at the problem of that the engineering disasters of rock burst, large deformation, etc. are prone to be caused by the buried depth and high geostress of Qinling Water Conveyance Tunnel, the stress testings on the hydraulic fracturing method are carried out on the typical locations (the Qinling Mountain-Crossing section, the south section of Qinling Mountain and the north section of Qinling Mountain ) at the site of the tunnel respectively, and then the 3-D geostress field inverse analyses of the section without fault and the section with fault are made for studying the characteristics and law of the initial geostress field of Qinling Water Conveyance Tunnel. The study result shows that the geostress of Qinling Water Conveyance Tunnel exhibits stronger tectonic stress effect, while the reconnaissance tests made on the south section of Qinling Mountain and the north section of Qinling Mountain show that the maximum horizontal principal stresses is 25.4~27.7 MPa and the direction of the maximum horizontal principal stress stabilizes to EW. The geostress distribution of Qinling Water Conveyance Tunnel can be better inversely analyzed by the numerical simulation concerned;from which most of the maximum principal stresses of the tunnel section without fault are 10~45 MPa and most of the minimum principal stresses are 0~15 MPa, while the values of the maximum horizontal principal stress along the main axis of the tunnel sections with fault are higher with the variation range of 20.46~71.94 MPa and the maximum is up to 71.94 MPa. Due to the existence of fault fracturing zone, strenuous stress variations are to occur at the areas nearby and the stress value inside the fault zones significantly decrease, but stress concentrations occur at both the sides of fault zones with the increase of local stress.
作者
赵力
张忠东
李立民
王朋
蒙晶
陶磊
ZHAO Li;ZHANG Zhongdong;LI Limin;WANG Peng;MENG Jing;TAO Lei(Hanjiang-to-Weihe River Valley Water Diversion Project Construction Co.,Ltd.,Xi'an 710010,Shaanxi,China;China Railway First Survey and Design Institute Group Co.,Ltd.,Xi'an 710043,Shaanxi,China)
出处
《水利水电技术》
北大核心
2019年第3期90-96,共7页
Water Resources and Hydropower Engineering
基金
国家重点研发计划资助项目(2016YFC0401802)
关键词
输水隧洞
地应力
水平应力
地质模型
反演分析
深部隧道工程
地下工程安全
工程地质灾害
water conveyance tunnel
geostress
horizontal stress
geological model
inverse analysis
deep tunnel project
safety of underground engineering
engineering geological hazards
