寒区隧道微台阶法快速开挖及台阶参数优化研究  

Study on Rapid Excavation by Micro-Step Method and Step Parameters Optimization in Cold-Region Tunnels

作　　者：张胜利 ZHANG Shengli(China Railway 16th Bureau Group 4th Engineering Co.Ltd.,Beijing 101400,China)

机构地区：[1]中铁十六局集团第四工程有限公司,北京101400

出　　处：《铁道建筑技术》2024年第11期192-195,200,共5页Railway Construction Technology

基　　金：中铁十六局集团有限公司科技研究开发计划课题(K2020-10C)。

摘　　要：台阶法在节省施工时间、提升机械化作业水平方面展现出了显著的优势,但在控制围岩稳定性与防止变形上存在一定的局限性。为了减少台阶法开挖对隧道围岩的变形影响,以崇礼隧道工程项目为依托,阐述了寒区隧道微台阶法快速开挖技术;并通过有限元模拟的方法,对台阶法施工时的台阶长度、高度进行优化,确定单线铁路隧道围岩采用台阶法施工时的台阶参数。结果表明:微台阶法施工时掌子面各工作区工序同步独立进行,互不干涉影响,有效提高了施工速度;Ⅳ级围岩上台阶高度取为4 m较为适宜,此时拱顶沉降和周边收敛较小,同时掌子面挤出变形也在控制范围之内;增加台阶长度可以保持隧道掌子面的稳定,但会增加拱顶沉降和周边收敛,因此上台阶长度并非越长越好,Ⅳ级围岩上台阶的长度宜控制在3 m。The step method shows significant advantages in saving construction time and improving the level of mechanized operation,but there are some limitations in controlling the stability of the surrounding rock and preventing deformation.In order to reduce the deformation impact of the step method on the tunnel surrounding rock,this paper,based on the Chongli Tunnel project,describes the rapid excavation technology of micro-step method for cold-region tunnels;and through the method of finite element simulation,it optimizes the length and height of the steps during the construction of the step method,and determines the parameters of the steps for the construction of the single-line railway tunnel surrounded by rock using the step method.The results show that:micro-step method construction of the tunnel face of the work area processes are carried out independently and synchronously,without interfering with each other,effectively improving the construction speed;Ⅳ surrounding rock on the step height of 4 m is more appropriate,at this time,the vault settlement and surrounding convergence are smaller,while the tunnel face extrusion deformation is also within the control range;increasing the length of the step can maintain the stability of the tunnel face,but it will increase the vault settlement and surrounding convergence.Therefore,the length of the upper step is not the longer the better,and the length of the upper step for class Ⅳ surrounding rock should be controlled at 3 m.

关 键 词：寒区隧道 微台阶法 围岩变形 参数优化 

分 类 号：U455.4[建筑科学—桥梁与隧道工程]