摘要
为研究藏北多龙矿集区某金铜矿现今地应力状态及断裂稳定性,采用水压致裂法对研究区域内三个钻孔深度171.90~751.40 m范围进行地应力测量,基于地应力实测数据,得出地应力及侧压系数随深度变化规律并分析了区域断裂稳定性。结果表明:研究区域应力场以水平构造应力为主,最大水平主应力(S_(H))和最小水平主应力(S_(h))分别为7.55~31.94 MPa和6.61~20.36 MPa,垂直主应力(S_(v))为4.56~20.29 MPa,且均随深度增加呈线性增大趋势;研究区域最大水平主应力优势方位为N-E向,应力结构主要为S_(H)>S_(h)>S_(v),表现为逆断型应力状态;侧压系数K、水平应力系数KHh及水平剪应力强度指标μ_(m)拟合结果表明,研究区域水平构造应力的主导作用随深度增加逐渐减弱,水平剪应力强度较低,但研究区域内A区水平剪应力强度明显高于B区;应用库仑摩擦滑动准则,分析区域断裂稳定性,研究区域应力积累水平较低,现今地应力状态未达到引起断裂失稳滑动的极限状态,当摩擦系数μ弱化到0.2时,断裂带才有发生失稳滑动的可能性。
To assess the current in-situ stress state and fracture stability of a gold-copper deposit in the Duolong ore concentration area,Northern Xizang,the hydraulic fracturing method and impression orientation method were employed alongside the HYF 3 single and dual-circuit in-situ stress testing system.This approach facilitated the measurement of in-situ stress across three boreholes at depths ranging from 171.90 m to 751.40 m.A total of 1397.20 m of drilling was conducted,which included in-situ stress measurements for 14 sections and maximum horizontal principal stress direction measurements for 3 sections.Utilizing the measured in-situ stress data,the variation patterns of in-situ stress and lateral pressure coefficients with depth were established,and a regional fracture stability analysis was performed.The results indicate that the stress field in the study area is predominantly influenced by horizontal tectonic stress,with maximum and minimum horizontal principal stresses(S_(H)and S_(h))ranging from 7.55 MPa to 31.94 MPa and 6.61 MPa to 20.36 MPa,respectively.The vertical principal stress(S_(v))ranges from 4.56 MPa to 20.29 MPa,with all stress components showing a linear increase with depth.The in-situ stress structure is primarily characterized by S_(H)>S_(h)>S_(v),indicating a reverse fault-type stress state.Predictive analysis based on the measured data suggests that the transition depth of the stress structure is approximately 746.18 m,below which the stress structure displays a strike-slip fault-type stress state.The maximum horizontal principal stress direction in the study area ranges from N14.30°E to N33.34°E,with a predominant northeast orientation.The distribution pattern of the lateral pressure coefficient(K)with depth indicates that the influence of horizontal tectonic stress is stronger in the shallow crust than at greater depths,gradually diminishing as depth increases.The fitting results for the horizontal stress coefficient(K Hh)and the horizontal shear stress intensity index(μ_(m))reveal that
作者
李洪超
刘轩泽
付俊
李社
吴灿萍
梁瑞
LI Hongchao;LIU Xuanze;FU Jun;LI She;WU Canping;LIANG Rui(Faculty of Public Safety and Emergency Management,Kunming University of Science and Technology,Kunming 650093,China;City College,Kunming University of Science and Technology,Kunming 650051,China;Kunming Prospecting Design Institute of China Nonferrous Metals Industry Co.,Ltd.,Kunming 650051,China;Yunnan Key Laboratory of Geotechnical Engineering and Geohazards,Kunming 650051,China;Xizang Jinlong Mining Co.,Ltd.,Lhasa 850000,China;Faculty of Land Resources Engineering,Kunming University of Science and Technology,Kunming 650093,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2024年第12期4659-4668,共10页
Journal of Safety and Environment
基金
2021云南省科技厅省重点实验室科技计划项目(科技人才与平台计划202105AG070006)
中国有色金属工业昆明勘察设计研究院有限公司科技创新项目(2022YN05A3,2023YN06)
国家自然科学基金项目(52164010,52364016)。
关键词
安全工程
地应力测量
水压致裂法
地应力状态
断裂稳定性
safety engineering
in-situ stress measurement
hydraulic fracturing method
in-situ stress state
fracture stability
