超大断面通航隧洞软弱围岩及支护体系受力变形特性研究  

Study on the Mechanical and Deformation Characteristics of Weak Surrounding Rock and Supporting System of Super-large Section Navigation Tunnel

作　　者：曾仲毅[1] 杨洪[1] 春军伟[1] 陈政 吴铭芳[1] ZENG ZhongYi;YANG Hong;CHUN Junwei;CHEN Zheng;WU Mingfang(Guizhou Transportation Planning Survey and Design Academe Co.,Ltd.,Guiyang 550081,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]贵州省交通规划勘察设计研究院股份有限公司,贵阳550081 [2]西南交通大学土木工程学院,成都610031

出　　处：《交通科技》2023年第5期91-96,共6页Transportation Science & Technology

基　　金：黔科合重大专项字[2018]3011资助。

摘　　要：文中以开挖面积为604 m 2的超大断面清水江通航隧洞为研究对象,以数值分析手段模拟超大断面软弱围岩隧道施工过程中围岩及支护体系受力变形特性。研究表明,隧洞开挖过程中,拱顶围岩变形影响区域较边墙大,但边墙处围岩受剪应力较拱顶围岩更高;采用长锚杆加固拱顶围岩,可取得较好效果,但长锚杆对边墙围岩加固作用不明显,边墙处更适宜采用短锚杆;隧洞临时支撑拆除前,下导坑临时侧壁弯矩、轴力急剧增大,接近屈服破坏;临时支撑拆除后,主洞初期支护受力明显增大,拱部和仰拱以受弯为主,边墙以受压为主,受力最不利位置为拱脚。Taking the super-large cross-section Qingshuijiang Navigation Tunnel with an excavation area of 604 m 2 as the analytic target,the mechanical and deformation characteristics of tunnel surrounding rock and support system are simulated and analyzed by means of numerical analysis.Results show that the deformation of the surrounding rock at the arch crown has a larger impact area than the side wall,and the shear stress of surrounding rock on both sides is higher than that of the top during tunnel excavation.Long bolt on the top of the tunnel can play a better role in reinforcing the surrounding rock.However,the reinforcement effect of long bolts on both side is not obvious,and the use of short anchor bolt is more suitable.Before the removing of temporary support of the tunnel,the axial force and bending moment of the lower pilot pit temporary side wall increases sharply,approaching yield failure.After the removing of temporary support,the stress of the initial support of the main tunnel increases significantly.The arch and inverted arch are mainly subjected to bending.The side walls on both sides are mainly subjected to compression.The arch foot is the weakest position of the structure.

关 键 词：通航隧洞 超大断面 围岩变形特性 隧洞支护体系 软弱围岩 

分 类 号：U451[建筑科学—桥梁与隧道工程]