中国铁道科学2018，Vol.39Issue(3)：49-56,8.DOI:10.3969/j.issn.1001-4632.2018.03.07
预切槽法开挖黄土隧道的切槽方式研究
Study on Slot Cutting Pattern for Excavation of Loess Tunnel by Pre-Cutting Method
摘要
Abstract
Combined with the need of carrying out field test with the currently developed central-axis pre-cutting machine,the ground settlement,deformation and stress state of the pre-arching with different sequential and jumping slot cutting patterns were studied by numerical method,four slot cutting patterns were compared which were sequential slot cutting with three,five,seven segments and jumping slot cutting with seven segments.To test the mechanical properties of the newly developed pre-cutting machine,a ring cutting and pouring concrete test was carried out on the site of Hongliangying loess tunnel on Baoji-Lanzhou passenger dedicated line.Results show that with the increase of slot-cutting segments,the ground settlement and the convergence deformation of the pre-arching diminish gradually.The sequential slot-cutting pattern with seven segments is the most favorable in controlling ground settlement and structure deformation.It is worth noting that in all the four slot cutting patterns,the arch foots of the pre-arching are in unfavorable stress state where excessive tensile stress appears and exceeds the ultimate tensile strength of concrete,and the stress of other parts of the pre-arching are all in safe range.Therefore,locked springing should be added at arch foot.In addition,the pre-arching should be strengthened in time to improve its tensile strength and prevent the failure of tunnel structure.Field test also shows that it is applicable to cut slot by segments in viscous loess with good slot stability,but it is not applicable in sandy loess,the qualities of slot and the cast-in-place pre-arching are poor in unstable ground.关键词
黄土隧道/预切槽法/切槽方式/地层沉降/预筑拱变形/预筑拱受力Key words
Loess tunnel/Pre-cutting method/Slot cutting pattern/Ground settlement/Pre-arching deformation/Stress of pre-arching分类
交通工程引用本文复制引用
王秀英,郑维翰,张隽玮,孟德鑫,王新东..预切槽法开挖黄土隧道的切槽方式研究[J].中国铁道科学,2018,39(3):49-56,8.基金项目
国家自然科学基金资助项目(51178026) （51178026）
中国铁路总公司科技研究开发计划项目(2013G011-C) （2013G011-C）
