大跨度软岩隧道施工中双层初期支护施作时机优化分析  

Optimization Analysis of Construction Timing of Double-layer Initial Support in Construction of Large-span Soft Rock Tunnel

作　　者：李涛[1] 刘瑞辉 王万平[1] 曹校勇[1] LI Tao;LIU Rui-hui;WANG Wan-ping;CAO Xiao-yong(CCCC First Highway Consultants Co.Ltd.,Xi'an 710075,China)

机构地区：[1]中交第一公路勘察设计研究院有限公司,西安市710075

出　　处：《公路》2023年第7期58-62,共5页Highway

基　　金：陕西省秦创原“科学家+工程师”队伍建设项目,项目编号2023KXJ-159。

摘　　要：为对比隧道台阶法施工中双层初期支护施作时机对隧道施工安全的影响,选取合理的支护时机,提高双层初期支护的安全性。以宝汉高速公路连城山大跨度隧道为依托,运用数值模拟的方法对比分析不同支护时机下双层初期支护的变形及受力特征。通过现场监测数据与模拟结果对比分析得出:当第二层初期支护施作时机在中台阶施作完成后时,能够充分发挥双层初期支护的作用效果,并使两层初期支护的变形和受力更加合理,保证了双层初期支护结构的安全性和经济性,对于指导类似地质条件下采用三台阶法施工的大跨度双层初期支护隧道的设计与施工具有重要意义。In order to compare the influence of double-layer initial support application timing on tunnel construction safety in tunnel step method construction,reasonable support timing should be selected to improve the safety of double-layer initial support.Numerical simulation is used to compare and analyze the deformation and force characteristics of double-layer initial support under different support timing based on the large span tunnel in Liancheng Mountain of Baoji-Hanzhong Expressway.By comparing the field monitoring data with the simulation results,it is concluded that when the second layer of initial support is applied after the middle step is completed,the effect of double-layer initial support can be fully fulfilled,and the deformation and force of the two layers of initial support is more reasonable,which ensures the safety and economy of the double-layer initial support structure,and is of great significance for guiding the design and construction of large-span double-layer initial support tunnels constructed by the three-step method under similar geological conditions.

关 键 词：隧道工程 台阶法 双层初期支护 大跨度隧道 软岩大变形 数值模拟 

分 类 号：U455.7[建筑科学—桥梁与隧道工程]