摘要
城市地铁暗挖车站施工中马头门既是结构的薄弱环节,也是工程施工过程中结构转换的关键环节。马头门开挖会改变原结构受力状态,若施工不当可能造成原结构变形,增大地表沉降,严重时甚至引起结构破坏。本文以在建项目北京地铁16号线红莲南里暗挖车站为例,在总结北京地铁车站暗挖马头门工程施工经验的基础上,分析了该工程地质及水文条件和周边环境等因素对地铁暗挖区间马头门工程施工风险的影响,系统地总结了竖井进入横通道马头门施工的一些关键的安全技术措施:(1)井壁密排钢格栅、在横通道的初期支护周边外设置加固环,很好的实现了结构受力转换;(2)打设双排超前小导管,对土体进行深孔注浆加固,防止土体失稳;(3)在马头门上方做加强腰梁,减小竖井的收敛变形;(4)破除马头门后,横通道施工采取预留核心土、控制台阶长度、控制格栅安装精度等开挖方法及支护措施。施工检测表明:各项监测值等均控制在设计允许范围内。
Urban subway construction is not only the structure of the weak links,and also an important factor in structural transformation in the process of engineering construction of ingate excavation changed the original structure stress,such as construction undeserved cause deformation of the original structure,increase the surface subsidence,serious when even cause structural damage.Taking honglian Nanliam Excavation station of Beijing Metro Line 16 as an example,this paper summarizes the construction experience of Beijing metro station underground excavation ma Tou gate project,and analyzes the inf luence of engineering geological and hydrological conditions and surrounding environment on the construction risk of ma Tou gate project in underground excavation section of subway,In this paper,some key safety technical measures for the construction of horse-head door of vertical shaft entering cross passage are systematically summarized;(1)reinforcement rings are set outside the initial support perimeter of the cross passage with dense row steel grille,which can well realize the structural stress conversion;(2)Double-row leading small pipe is set to reinforce the soil with deep hole grouting to prevent the soil from instability;(3)Strengthen the waist beam above the horse's head door to reduce the convergent deformation of the shaft;(4)After the horse head door was broken,the excavation methods and support measures,such as reserving the core soil to control the step length to control the installation precision of the grid,were adopted in the construction of the cross passage.The results showed that all the monitoring values were controlled within the allowable design range.
作者
侯锐
HOU Rui(Beijing Municipal Fourth Construction Engineering Co.,Ltd.,Beijing,100000 China)
出处
《科技创新导报》
2020年第35期35-38,共4页
Science and Technology Innovation Herald
关键词
地铁暗挖车站
马头门
腰梁
加固环
超前注浆加固
Underground excavation station
Matou Gate
Waist rail
Reinforcement ring
Advance grouting reinforcement
