高地应力下顺层偏压隧道开挖变形控制技术研究  

Study on Deformation Control Technology for Unsymmetrically Loaded Tunnels in Bedding Strata under High Geo-stress

作　　者：于国亮 娄义黎 吴国鹏 施成华[2,3] 郑可跃 YU Guoliang;LOU Yili;WU Guopeng;SHI Chenghua;ZHENG Keyue(China Railway 17th Bureau Group Fourth Engineering Co.Ltd.,Chongqing 401121;School of Civil Engineering,Central South University,Changsha 410075;National Engineering Research Center for High-speed Railway Construction Technology,Changsha 410075)

机构地区：[1]中铁十七局集团第四工程有限公司,重庆401121 [2]中南大学土木工程学院,长沙410075 [3]高速铁路建造技术国家工程研究中心,长沙410075

出　　处：《现代隧道技术》2022年第5期237-245,共9页Modern Tunnelling Technology

基　　金：国家自然科学基金资助项目(5217082631).

摘　　要：中老昆万铁路甘庄隧道在施工过程中出现高地应力顺层偏压大变形,引起了隧道初期支护开裂、掉块、侵限等问题。针对甘庄隧道大变形问题,基于三台阶开挖法,提出变种短台阶施工控制技术,并采用块体离散元软件3DEC开展不同台阶高度和长度下隧道开挖数值模拟。结果表明,台阶参数对顺层偏压隧道变形影响显著,中台阶高度从4 m减小至2 m,隧道变形收敛急剧减小;当中台阶长度小于15 m时,增大中台阶长度,隧道变形收敛逐渐减小,当中台阶长度大于15 m,隧道变形收敛趋于稳定,变形收敛稳定在21 cm左右。对于甘庄隧道顺层偏压段中台阶高度应设置在2 m左右,长度应控制在15 m以上,现场监测数据表明该施工控制技术在甘庄隧道取得了良好的变形控制效果。During the construction of Ganzhuang Tunnel on the China/Kunming-Laos/Vientiane Railway,large deformation occurred due to high geo-stress and unsymmetrical load in bedding strata,which resulted in the cracking of tunnel primary support,block dropping and clearance invasion.Aiming at the large deformation of Ganzhuang tunnel,based on the three bench excavation method,a modified short bench construction control technology is proposed,and the block discrete element software 3DEC is used to carry out numerical simulation of tunnel excavation under different bench heights and lengths.The results show that the bench parameters have a significant effect on the deformation of the unsymmetrically loaded tunnel in bedding strata.When the height of the middle bench decreases from 4 m to 2 m,the tunnel deformation convergence decreases rapidly;When the length of the middle bench is less than 15 m,the deformation convergence of the tunnel decreases gradually with the increase of the length of the middle bench.When the middle bench length is greater than 15 m,the tunnel deformation convergence tends to be stable,and the tunnel deformation convergence is about 21 cm.The height of the middle bench in the bedding unsymmetrical loading section of Ganzhuang tunnel should be set at about 2 m,and the length of the middle bench should be controlled at more than 15 m.Field monitoring data show that this construction control technology has achieved good deformation control effect in Ganzhuang tunnel.

关 键 词：顺层偏压 大变形 开挖工法 3DEC 控制技术 

分 类 号：U455[建筑科学—桥梁与隧道工程]