偏压作用下超大断面双连拱隧道中隔墙受力变形特性分析  

Analysis of Mechanical and Deformation Characteristics of Partition Wall of Double⁃arch Tunnel with Large Cross Section Under Biased Pressure

作　　者：李玉华[1] LI Yuhua(China Railway 18th Bureau Group Co.,Ltd.,Tianjin300222,China)

机构地区：[1]中铁十八局集团有限公司,天津300222

出　　处：《施工技术（中英文）》2022年第13期91-95,128,共6页Construction Technology

基　　金：福建省交通运输科技项目(202001)。

摘　　要：中隔墙的安全稳定是影响双连拱隧道施工安全的重要因素,施工过程中其受力变形特性是工程中十分关注的问题。结合某偏压作用下超大断面双连拱隧道工程,考虑地质条件和非对称开挖的影响,利用理论分析和数值模拟的方法对比分析了三导洞、中导洞正洞台阶法、中导洞全断面法施工过程中中隔墙力学变形特性。研究表明:双连拱隧道结构形式一定时,不同施工方法得到的中隔墙最终应力变形量较为接近,但由于施工过程中应力和变形随开挖区域不同而存在较大差异;受偏压和非对称开挖影响,中隔墙会产生向先期开挖侧旋转的趋势,且在靠近偏压一侧会出现较大的应力集中区域;优化后的“中导洞+双侧壁开挖”施工方法能保证围岩的稳定且各项监测指标正常,保障了工程安全进行。The safety and stability of the partition wall is an important factor that affects the construction safety of the double⁃arch tunnel.During the construction process,the mechanical deformation characteristics of the wall are very concerning issues in engineering.In combination with a double⁃arch tunnel with a super⁃large cross⁃section under a certain bias pressure,this paper,taking the influence of geological conditions and asymmetrical excavation into consideration with theoretical analysis and numerical simulation methods,comparatively analyzes the mechanical deformation characteristics of the partition wall during the construction of three guide tunnel and mid⁃guiding hole with the bench method,and the middle pilot tunnel with the whole section method.The research shows that:when the structure of the double⁃arch tunnel is fixed,the final stress⁃deformation of the partition wall obtained by different construction methods are relatively close,but the stress and deformation during the construction process vary greatly with the different construction processes.Due to the bias pressure and the asymmetrical excavation,the partition wall tends to rotate towards the pre⁃excavation side and there will be a large stress concentration area near the bias side.The optimized method of middle pilot tunnel plus double side wall excavation can ensure the stability of the surrounding rock and regular monitoring indicators,ensuring the safety of the project.

关 键 词：隧道 双连拱 偏压 中隔墙 应力 变形 监测 

分 类 号：U455.5[建筑科学—桥梁与隧道工程]