中老铁路盐岩地层隧道断面型式研究  

Study on Tunnel Section Types in Salt Rock Strata forthe China-Laos Railway

作　　者：赵万强[1] 李金宜 罗禄森[1] 王志杰[2] ZHAO Wanqiang;LI Jinyi;LUO Lusen;WANG Zhijie(China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China;MOE Key Laboratory of Transportation Tunnel Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]中铁二院工程集团有限责任公司,成都610031 [2]西南交通大学交通隧道工程教育部重点实验室,成都610031

出　　处：《高速铁路技术》2024年第5期92-99,共8页High Speed Railway Technology

摘　　要：中老铁路盐岩地层隧道施工中出现基底塌陷、衬砌开裂等病害。为保证该隧道安全施工和健康服役,采用现场勘探、数值计算、理论分析、监控量测等方法对隧道断面型式进行研究。结果表明:(1)蛋形断面围岩变形略小于原马蹄形断面,但塑性区面积大幅增加;椭圆形、圆形断面有利于围岩稳定;(2)马蹄形断面拱顶存在应力集中,蛋形断面墙脚应力较大,椭圆形、圆形断面受力均匀,且椭圆形安全系数大于圆形;(3)将断面面积、衬砌周长、洞周变形率、围岩塑性区面积比、最小安全系数作为评价指标,综合考虑施工因素,圆形断面型式最优;(4)隧道采用圆形断面施工后,围岩变形、应力大幅度减小,衬砌无裂缝,仰拱底鼓情况改善。During the construction of tunnels in salt rock strata for the China-Laos Railway,issues such as base collapse and lining cracks have emerged.To ensure the safe construction and healthy operation of these tunnels,a comprehensive study on tunnel section types was conducted using methods including field exploration,numerical calculations,theoretical analysis,and monitoring measurements.The results indicate:(1)The deformation of surrounding rock in the egg-shaped section is slightly less than that in the original horseshoe-shaped section,but the plastic zone area increases significantly.Elliptical and circular sections are more conducive to the stability of surrounding rock.(2)Stress concentration occurs at the vault of the horseshoe-shaped section,while the wall feet of the egg-shaped section experience higher stresses.Elliptical and circular sections exhibit uniform stress distribution,with the elliptical section having a higher safety factor than the circular one.(3)Considering the section area,lining perimeter,deformation rate around the tunnel perimeter,ratio of plastic zone area in surrounding rock,and minimum safety factor as evaluation indicators,along with construction factors,the circular section type is determined to be the optimal choice.(4)After adopting the circular section for tunnel construction,the deformation and stress of surrounding rock are significantly reduced,no cracks are observed in the lining,and the uplift of the invert is improved.

关 键 词：铁路隧道 盐岩地层 断面型式 数值计算 层次分析法 现场量测 

分 类 号：U459.1[建筑科学—桥梁与隧道工程]