V级围岩大断面隧道施工法数值分析

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关键词：铁路客运专线；围岩变形；支护结构；V级软弱破碎岩体；隧道施工；有限元法中图分类号：TU94 文献标志码：A 文章编号:1003-5168(2025)20-0058-06DOI: 10.19968/j.cnki.hnkj.1003-5168.2025.20.012

Numerical Analysis of Construction Methods for Large Cross-Section Tunnels in ClassVSurrounding Rock

DU Yi (China Railway 12th Bureau Group the 2nd Engineering Co.,Ltd.,Taiyuan O3Oo32, China）

Abstract: [Purposes] This study numerically analyzes two primary construction methods—the CD method and the Three-Bench Seven-Step method—for tunnels in Class V weak and fractured rock mass. The aim is to determine their comparative advantages and disadvantages during construction and to provide a reference for similar projects.[Methods] Taking the Fuyan No.1 Tunnel on the Jilin-Hunchun High-Speed Railway as a case study,the finite element method was employed to compare the effects of the two methods on the excavation process,focusing on the stress and deformation characteristics of the surrounding rock and supporting structures.[Findings] The results indicate that the CD method,utilizing a multi-drift approach to convert a large span into smaller ones,reduces ground disturbance.Relying on the support provided by the middle partition,it effectively controls the deformation of both the structure and the surrounding rock.The Three-Bench Seven-Step method stabilizes the tunnel face by leaving a core soil,thereby reducing face extrusion displacement.Regarding the controlofcrown settlement, sidewall convergence,and surface subsidence,the CD method performs better than the Three-Bench Seven-Step method.Both methods induce tensile stresses exceeding the alowable limit at the crown, shoulders,and haunches,necessitating advance reinforcement; however,the forces in the pipe roof re

main within the code's allowable range.[Conclusions] For tunnel construction in Class V weak and fractured rock mass,the CD method demonstrates better performance in controlling surrounding rock deformation,whilethe Three-Bench Seven-Step method offersadvantages in face stability.Both methods require appropriate advance support measures to ensure construction safety.

Keywords: railway passenger dedicated line; surrounding rock deformation; supporting structure; Class V weak and fractured rock mass; tunnel construction; finite element method

0 引言

我国是一个多山的国家，山区面积约占国土总面积的 70%[1] ，尤其是西南地区地形构造复杂，且山地较多，在山区建设铁路和公路时必然会遇到地形障碍，采用隧道穿越山区是不可避免的。（剩余8295字）