软弱围岩隧道斜井转正洞设计与施工技术

分析目前隧道施工斜井转正洞存在的问题,并结合山西中南部铁路通道西铁车2号隧道工程实际,介绍斜井转正洞采用喇叭口过渡、相交处门架、门式小导洞进正洞的设计方案以及相关施工要点,且说明施工注意事项。斜井进正洞过渡段喇叭口形式可显著提高施工工效,减少施工过程中交叉作业的安全隐患,同时,利用断面特点可有效地抵消交叉口处正洞初期支护对斜井的纵向推力作用。

Design and Construction Technology for the Intersection Point between Inclined Shaft and Main Tunnel in Soft and Weak Surrounding Rocks

This paper analyzes the problems which exist in construction of the intersection point between inclined shaft and main tunnel at present.Afterwards,taking the Xitieche No.2 Tunnel of Central and Southern Shanxi Railway as an example,this paper introduces the design schemes and their construction key points,including the transition section by using the bell mouth at the intersection point between inclined shaft and main tunnel,the portal frame at the intersection point,and the portal-type small tunnel heading at the intersection point.Also,this paper describes the matters needing attention in construction.The paper thinks that,by using the bell mouth at the intersection point between inclined shaft and main tunnel,the construction efficiency can be improved remarkably,and the potential safety hazards during the overlapping operations can be reduced.At the same time,by using the features of the cross sections,the longitudinal thrust force can be counteracted effectively,which is acted on the inclined shaft by the primary support of main tunnel at the intersection point.