工程地质学报2024，Vol.32Issue(3)：1098-1111,14.DOI:10.13544/j.cnki.jeg.2023-0455
深部极高地应力花岗岩隧道岩爆破坏特征及成因机理研究
ROCKBURST FAILURE CHARACTERISTICS AND FORMATION MECHA-NISM OF DEEP GRANITE TUNNEL WITH EXTREMELY HIGH GEO-STRESS
摘要
Abstract
During the construction of a deep granite tunnel with extremely high geo-stress,rockburst disasters are extremely serious.The rock mass flakes off,forms slab-shaped fractures,and violently ejects rocks due to rock-bursts.To reveal the formation mechanism of rockbursts in the granite tunnel,the formation,characteristics,and influencing factors of tunnel high geostress and rockbursts were discussed and analyzed.This includes engineering geological survey,monitoring and measurement,rockburst record statistics,indoor rock mechanics tests,micro-scopic analysis,numerical simulation,et al.According to statistical analysis of rockburst records,rockburst disas-ters are prominent in the construction of the granite tunnel,with complex and diverse damage characteristics and concentrated occurrence times.When affected by horizontal tectonic stress,the intensity of rockbursts near the side of the Yarlung Zangbo valley increases significantly,and when controlled by vertical stress,rockbursts are mainly distributed on the face and vault.Based on measured in-situ stress data of boreholes and inversion analysis of the in-itial geostress field,the granite tunnel is dominated by horizontal tectonic stress and vertical stress.82.0％of the area along the tunnel is in a state of high to extremely high geo-stress,providing internal dynamic geological condi-tions for the occurrence of rock bursts.Laboratory rock mechanics tests show that both monzogranite and granodiorite have a moderate rockburst tendency,and the rock mass with thick layers,high strength,high stiffness,and integri-ty provide sufficient provenance conditions for rockbursts.Controlled by the special tectonic structure of the Yarlung Zangbo suture zone and the influence of Cenozoic magmatic activities,the granite tunnel presents high geothermal characteristics with a geothermal gradient of 5.5 ℃/100m,and the highest measured ground temperature reached 89.6 ℃.The high-temperature thermo-mechanical coupling accelerates the occurrence of rockburst and increases the rockburst risk level.The quality of tunnel construction technology will change the stress redistribution of sur-rounding rock,affect the stress concentration of surrounding rock,cause a certain size effect,and affect the intensi-ty level,time,and spatial distribution of rockburst.关键词
花岗岩隧道/极高地应力/岩爆破坏特征/成因机理/高地温/岩爆倾向性Key words
Granite tunnel/Extremely high geo-stress/Rockburst failure characteristics/Formation mechanism/High temperature/Rockburst tendency分类
土木建筑引用本文复制引用
周航,张广泽,赵晓彦,陈明浩,陈仕阔,喻炳鑫..深部极高地应力花岗岩隧道岩爆破坏特征及成因机理研究[J].工程地质学报,2024,32(3):1098-1111,14.基金项目
国家自然科学基金项目(资助号:41672295),四川省科技计划项目(资助号:2019YFG0047),中国中铁股份有限公司科技研究开发计划(资助号:2021-重点-02),中铁二院科研项目(资助号:KDNQ214100,KSNQ222015,KSNQ232025).This research is supported by the National Natural Science Foundation of China(Grant No.41672295),Sichuan Provincial Science and Technology Plan Project(Grant No.2019YFG0047),China Railway Co.,Ltd.Science and Technology Research and Development Plan(Grant No.2021-重点-02)and China Railway Eryuan Engineering Group Co.,Ltd.,Funding(Grant Nos.KDNQ214100,KSNQ222015,KSNQ232025). （资助号:41672295）
