摘要
输水洞与斜井交叉口处围岩为第三系N1+2泥岩,空间三维受力复杂,尤其正洞横向挑顶开挖支护难度较大,工作面小,安全、质量隐患多,开挖支护不当很容易发生大变形,危及施工安全。为此,通过在支洞交叉口部设置加强环承受上部地层应力,小导洞挑顶爬升至正洞拱部进行施工,将主洞钢拱架一侧支撑在加强环横梁上,保证支护结构安全稳固,实现了斜井支洞进入主洞施工安全。
As the surrounding rock around the intersection between the water-conveying tunnel and the oblique shaft is tertiary N(1+2)mudstone,the three dimensional stress in space there is complex,and especially the excavation from the oblique shaft to the main tunnel is very difficult owing to the small work face,in which case there exist quite a few potential accidents in both safety and quality.If supporting for the excavation is not properly carried out great deformation tends to happen,which may endanger the safe construction.In such a case,a strengthening ring is provided at the intersection of the branch tunnel to bear the stress of the upper strata,the top picking of the small pilot drifts will be performed at the arch of the main tunnel,and one side of the steel arch centering of the main tunnel will be placed onto the crossbeam of the strengthening ring so as to make the supporting structure secure and stable,and ensure the safe construction of the oblique shafts into the main tunnel.
作者
孙军
SUN Jun(The 3rd Engineering Co. Ltd of the 14th Bureau Group of China Railway,Jinan 272100,China)
出处
《国防交通工程与技术》
2020年第5期43-46,共4页
Traffic Engineering and Technology for National Defence
关键词
输水隧洞
第三系N1+2泥岩
斜井进入主洞
大变形
water-conveying tunnel
tertiary N(1+2)mudstone stratum
oblique shaft into the main tunnel
great deformation
