摘要
关角隧道需穿越1100m长第四系冲洪积砂质黄土、细砂及粉质黏土层地段。因风积砂层结构松散,黏聚力低、抗剪强度小、自稳能力差,在外力作用下极易松散、破碎,以致诱发围岩坍塌、冒顶等事故,施工风险高。基于此,针对浅埋风积砂层段隧道施工进行稳定性特征分析,并从开挖稳定性控制、支护变形控制等方面展开探讨,形成了风积砂层安全施工技术体系,总结出超前管棚支护、四台阶+扩大拱脚与筛子网双层支护体系等技术措施,避免了隧道塌方、支护变形等风险,同时可为类似工程建设提供可靠经验。
The construction of Guanjiao Tunnel will inevitably cross the section of 1100 m long quaternary alluvium,pluvial sandy loess,fine sand and silty clay layers.Due to the loose structure of aeolian sand layer,low cohesion,small shear strength and poor seK-stability ability,it is easy to be loose and broken under the action of external forces,which leads to the collapse of the surrounding rock,roof falling and other accidents and is of high construction risk.Based on the above,the stability characteristics of shallow-buried aeolian sand layer tunnel construction are analyzed,and discussion is carried out from the aspects of the excavation stability control,support deformation control to form the aeolian sand layer safety construction technology system.Then,the technical measures such as advanced pipe shed support,four steps adding extended arch foot and screen mesh double-layer support system are summarized,which can avoid risks of tunnel collapse and support deformation.At the same time,it provides reliable experience for similar engineering construction.
作者
刘万生
LIU Wansheng(China Railway 16th Bureau Group 1st Engineering Co.Ltd.,Beijing 101300,China)
出处
《铁道建筑技术》
2020年第10期135-139,共5页
Railway Construction Technology
基金
青海省科技支撑项目(2013-J-122)。
关键词
浅埋
风积砂层
隧道施工
关键技术
shallow burial
aeolian sand layer
tunnel construction
key technology
