新建立交隧道施工对既有隧道影响的模型试验  

Model test of influence of excavating new interchange tunnel on existing tunnel

作　　者：刘新荣[1,2] 王吉明[1,2] 郭子红[1,2,3] 林志[4] 裴丽[1,2] 

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045 [3]四川农业大学城乡建设学院,四川都江堰611830 [4]重庆交通科研设计院,重庆400067

出　　处：《重庆大学学报（自然科学版）》2012年第12期84-93,共10页Journal of Chongqing University

基　　金：国家863计划项目(2007AA11Z110);国家自然科学基金创新群体基金(50621403)

摘　　要：为分析新建立交隧道施工对既有隧道的影响,采用公路隧道结构与围岩综合试验系统对立交隧道进行三维物理模型试验。对既有隧道2个剖面的围岩压力、围岩内部位移及支护内力进行全程监测,通过分析得出:既有隧道Ⅰ剖面围岩压力受到的影响较大,Ⅱ剖面围岩压力受到的影响较小,各监测点的围岩压力基本处于减小状态,拱底围岩的稳定性降低;拱顶和拱腰围岩内部位移表现为拉伸变形,且拱顶处的变化值远大于拱腰处的变化值;既有隧道支护轴力变化的最终值基本为增加,支护弯矩变化的最终值都为减小;0.25D立交间距下既有隧道的围岩压力、内部位移及支护内力受新建隧道的影响较大,建议将立交隧道的立交间距控制在0.5D以上。In order to analyze the influence of construction of new interchange tunnel on existing tunnel,a three-dimension model test of interchange tunnel is carried out with the system of structure and surrounding rockmass of highway tunnel.Existing tunnel＇s surrounding rock pressure,internal displacement and supporting internal force are measured.The results show that,firstly,excavating new tunnel has obvious influence on section Ⅰ of existing tunnel,and has little influence on section Ⅱ.All surrounding rock pressure keeps decreasing and arch bottom surrounding rock＇s stability reduces.Secondly,crown and hance internal displacement manifest tensile deformation,and the deformation at crown is bigger than that at hance.Thirdly,exiting tunnel＇s supporting axial force keeps increasing and supporting moment keeps decreasing.Finally,excavating new interchange tunnel has obvious influence on exiting tunnel＇s surrounding rock pressure,internal displacement and supporting internal force when adjacent space is 0.25D,and it indicates that interchange tunnel＇s adjacent space should be no less than 0.5D.

关 键 词：立交隧道 既有隧道 围岩压力 支护内力 

分 类 号：U451[建筑科学—桥梁与隧道工程]