高地应力挤压性围岩隧道交叉段变形及结构力学特性研究  

Study on deformation and structural mechanics characteristics of intersection sections in high stress ground squeezing surrounding rock tunnels

作　　者：胡辉[1] 田浩晟 杨文波[1] 董沐野 周扬[1] 尤著刚 HU Hui;TIAN Haosheng;YANG Wenbo;DONG Muye;ZHOU Yang;YOU Zhugang(Key Laboratory of Transportation Tunnel Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu,Sichuan 610031,China)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,四川成都610031

出　　处：《岩石力学与工程学报》2024年第8期1952-1965,共14页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(52378413);四川省杰出青年科技人才项目(2022JDJQ0018)。

摘　　要：为探究隧道交叉段的非对称变形特征与结构破坏形式,提出挤压性大变形下交叉口的合理型式与适宜支护体系,以丽香铁路玉龙雪山隧道为工程背景,基于现场监测,对交叉段的结构变形与偏压特征进行研究,在此基础上通过数值模拟,分析交叉口影响范围以及合理交叉口型式对隧道支护效果的影响。研究结果表明:交叉段的支护结构在挤压性围岩作用下,呈现出显著的非对称变形与偏压特征,支护破坏多发生于拱肩、拱腰;平导以45°斜交段汇入主洞再扩挖,锐角侧与钝角侧主洞支护存在应力集中,锐角侧支护应力值更大、变形值更小,结构偏压严重;在锐角侧的主洞结构偏压方向与距离交叉口的距离有关,在距离为0.98D~1.26D时结构偏压方向出现反转;对比45°斜交叉口,“h型”交叉口在分配主洞轴向应力、洞周应力和变形上更加合理。In order to investigate the asymmetric deformation characteristics and structural damage patterns in tunnel intersections,and to propose the reasonable type and suitable support system for the intersection under the extrusion deformation,the Yulong Snow Mountain Tunnel of Lijiang-Shangri-La Railway is selected as the engineering background in this paper,and based on the field monitoring,the investigation on the structural deformation and biased-pressure characteristics of the intersections sections is performed.On this foundation,the influence range of the intersection is analyzed through numerical simulation to investigate the influence of reasonable intersection type on the tunnel support effect.According to the results of the study,the intersection support structure,under the action of extruded surrounding rock,shows significant asymmetric deformation and biased-pressure characteristics.The support damage mostly occurs at the arch shoulder and arch waist.When a parallel guide tunnel intersects the main tunnel at 45°and is subsequently further excavated,stress concentration is observed on both the acute and obtuse sides ofthe main tunnel's support,with the acute side experiencing higher stress levels and less deformation,indicating a severe structural biased pressure.The direction of structural biased pressure on the acute side of the main tunnel is related to the distance from the intersection,with a reversal in biased-pressure direction occurring between distances of 0.98D and 1.26D.Compared to 45°skewed intersections,h-shaped intersections prove more effective in distributing the main tunnel's axial stress,circumferential stress,and deformation.

关 键 词：隧道工程 铁路隧道 高地应力 挤压性大变形 交叉段 现场监测 

分 类 号：U45[建筑科学—桥梁与隧道工程]