摘要
为进一步研究富水岩溶铁路隧道超前支护方案的加固效果,文章以天坪隧道富水岩溶段为背景,采用FLAC3D数值计算软件建立岩溶大断面铁路隧道模型,对于大管棚加小导管注浆综合超前支护以及小导管注浆超前支护加固方案进行了优选分析。分析结果表明,大管棚加小导管综合超前支护相比较小导管注浆超前支护加固效果更加稳定:(1)衬砌结构位移变化方面,拱顶沉降最大值减小15.7%,上台阶水平收敛最大值减小19.4%;(2)掌子面挤出变形方面,中台阶上部掌子面挤出变形有所改善,其中上台阶水平收敛掌子面挤出变形量减小4.58%,中台阶水平收敛掌子面挤出变形量减小4.83%;(3)初期支护结构应力状态方面,最大压应力减小4.53%,最大拉应力减小15.6%。(4)相比较小导管注浆超前支护方案,大管棚加小导管综合超前支护方案更加适合富水岩溶大断面铁路隧道施工,研究成果可为类似隧道工程设计及施工提供参考。
In order to further study the reinforcement effect of the advance support scheme for the railway tunnel in water-rich karst area,based on the water-rich karst section of Tianping tunnel,FLAC3D numerical calculation software is adopted to establish the large-section railway tunnel model and the optimization analysis is made on the comprehensive advance support scheme with large pipe roof+small pipe and the advance support reinforcement scheme with small pipe grouting in the paper.The research results show that the comprehensive advance support with large pipe roof+small pipe is more stable than that with small pipe:(1)for the displacement change of lining structure,the maximum settlement of arch crown is reduced by 15.7%,and the maximum horizontal convergence of upper bench is reduced by 19.4%;(2)for the extrusion deformation of working face,the extrusion deformation of the upper working face of the middle bench is improved,in which the extrusion deformation of horizontal convergence working face of the upper bench is reduced by 4.58%,and that of the middle bench is reduced by 4.83%;(3)for stress state of initial supporting structure,the maximum compressive stress is reduced by 4.53%,and the maximum tensile stress is reduced by 15.6%;(4)Compared with the advance support scheme with small pipe,the comprehensive advance support scheme with large pipe roof+small pipe is more suitable for the construction of large-section railway tunnel in water-rich karst area.The research results can provide reference for design and construction of similar tunnel.
作者
崔光耀
朱建伟
姜冲
王立川
祁家所
CUI Guangyao;ZHU Jianwei;JIANG Chong;WANG Lichuan;QI Jiasuo(North China University of Technology,Beijing 100144,China;The First Construction Division Co.,Ltd.of China Railway Tunnel Group,Chongqing 401123,China)
出处
《高速铁路技术》
2020年第1期27-31,共5页
High Speed Railway Technology
基金
国家自然科学基金项目资助(51408008)
中铁隧道局集团有限公司科技创新计划(隧研合2013-01)
关键词
隧道工程
富水岩溶
大断面
超前支护
加固方案
tunnel works
water-rich karst
large section
advance support
reinforcement scheme
