临海超大断面双连拱隧道非对称开挖对围岩稳定性的影响  

Influence of Asymmetric Excavation on the Stability of Surrounding Rock in Coastal Super Large Section Double-Arch Tunnel

作　　者：甄孟芹 ZHEN Mengqin(China Railway 18th Bureau Group 1st Engineering Co.Ltd.,Zhuozhou Hebei 072750,China)

机构地区：[1]中铁十八局集团第一工程有限公司,河北涿州072750

出　　处：《铁道建筑技术》2025年第3期180-184,共5页Railway Construction Technology

基　　金：福建省交通运输科技项目(202106)。

摘　　要：临海超大断面双连拱隧道因结构特殊,开挖时围岩力学条件复杂,需严格控制开挖方式。本文采用非对称开挖方式,通过数值模拟分析围岩应力应变及变形,并用洞室位移实测数据验证。结果表明,在非对称开挖过程中,围岩应力随着开挖过程不断重新分布,各开挖步骤中围岩的最大应力主要出现在各开挖步骤隧道结构的尖角处,在拆除左洞临时支护做三衬时,围岩产生了一次较大的应力释放,随着开挖过程的不断进行,围岩应力逐渐趋于稳定;其次,2号和5号洞上部断面掘进时均出现隧道拱顶最大位移,左、右洞水平位移量在掘进支护完成后基本一致;最后,将数值模拟结果与洞室实测位移数据进行对比,两者总体误差范围在6%~11%之间,更准确地反映出围岩力学行为在超大断面双连拱隧道非对称开挖过程中的变化规律,为同类工程设计提供借鉴。Given its unique structural characteristics,the coastal super large section double-arch tunnel requires strict control over the excavation method due to the complex mechanical conditions of the surrounding rock during excavation.This article adopts asymmetric excavation method,analyzes the stress,strain and deformation of surrounding rock through numerical simulation,and verifies it with measured displacement data of the tunnel.The results indicate that during asymmetric excavation,the stress in the surrounding rock continuously redistributes with the excavation process.The maximum stress in the surrounding rock during each excavation step mainly occurs at the sharp corners of the tunnel structure.When the temporary support of the left tunnel is removed to make the third lining,a large stress release occurs in the surrounding rock.As the excavation process continues,the stress in the surrounding rock gradually stabilizes.Additionally,during the excavation of the upper section of tunnels 2 and 5,the maximum displacement of the tunnel arch is observed,and the horizontal displacement of the left and right tunnels is basically the same after the excavation support is completed.Finally,the numerical simulation results are compared with the measured displacement data of the tunnel,and the overall error range of the two is between 6%and 11%,which more accurately reflects the variation law of the mechanical behavior of the surrounding rock during the asymmetric excavation process of the super large section double arch tunnel,providing reference for similar engineering designs.

关 键 词：双连拱隧道 超大断面 非对称开挖 有限元 围岩稳定性 临海隧道 

分 类 号：U455.4[建筑科学—桥梁与隧道工程] U452[交通运输工程—道路与铁道工程]