In-situ observations of damage-fracture evolution in surrounding rock upon unloading in 2400-m-deep tunnels

作     者：Haosen Guo Qiancheng Sun Guangliang Feng Shaojun Li Yaxun Xiao Haosen Guo;Qiancheng Sun;Guangliang Feng;Shaojun Li;Yaxun Xiao

作者机构：Jiangxi Key Laboratory of Disaster Prevention-mitigation and Emergency ManagementNanchang 330013China Key Laboratory of Geological Hazards on Three Gorges Reservoir AreaMinistry of EducationYichang 443002China College of Civil Engineering and ArchitectureChina Three Gorges UniversityYichang 443002China State Key Laboratory of Geomechanics and Geotechnical EngineeringInstitute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China 

出 版 物：《International Journal of Mining Science and Technology》 (矿业科学技术学报（英文版）)

年 卷 期：2023年第33卷第4期

页      面：437-446页

核心收录：

学科分类：081406[工学-桥梁与隧道工程] 08[工学] 0814[工学-土木工程] 082301[工学-道路与铁道工程] 0823[工学-交通运输工程] 

基　　金：supported by the National Natural Science Foundation of China(Nos.51909136 and 42177168) Project of Youth Inno vation Promotion Association of Chinese Academy of Sciences(No.2021326) the Open Research Fund of Key Laboratory of Geological Hazards on Three Gorges Reservoir Area(China Three Gorges University),Ministry of Education(No.2020KDZ03) 

主　　题：Deep tunnel Fractured zone Damaged zone In-situ observation Unloading of rock mass 

摘      要：The damage-fracture evolution of deep rock mass has obvious particularity,which is revealed in 2400-mdeep tunnels by field *** evolution of the excavation damaged zone depth is consistent with that of the fractured zone *** ratio of the excavation damaged zone depth to the excavation fractured zone depth is greater than 2.0 in a rock mass with both high strength and good integrity,but less than1.5 in a rock mass with lower strength or poor *** disintegration in a rock mass with high strength and fair integrity is more likely to occur when it contains more than two groups of primary fractures in damaged *** develop outward in zonal disintegration but are totally different from the single-zone fracture,in which the fractures develop inward,and it is the starting position of the fractured zone when the excavation surface of the middle pilot is 7–9 m close to the pre-set borehole and it stops after the excavation surface of the baseplate is 11–14 m *** most intense evolution occurs around 2–4 m from the pre-set borehole in the sidewall expansion *** research results provide a reference for the monitoring scheme and support design of CJPL-Ⅲin its future construction.