不同开挖方法对浅埋黄土分岔隧道受力特性的影响  

Influence of Different Excavation Methods on Stress Characteristics ofShallow Buried Loess Bifurcation Tunnel

作　　者：邵志远 SHAO Zhiyuan(China Railway 22nd Bureau Group First Engineering Co.Ltd.,Harbin Heilongjiang 150006,China)

机构地区：[1]中铁二十二局集团第一工程有限公司,黑龙江哈尔滨150006

出　　处：《铁道建筑技术》2024年第1期115-119,185,共6页Railway Construction Technology

基　　金：中国铁建股份有限公司科技研发计划项目(2022-C26)。

摘　　要：为优化浅埋黄土分岔隧道的施工方法,依托白石二号隧道采用中导洞法和三导洞法对分岔处的受力和变形特性进行了分析。结果表明:(1)受施工工序转换影响,分岔处拱顶沉降和拱脚的水平位移变化趋势复杂,开挖后中导洞法左右洞拱顶沉降分别为-28.62 mm和-29.95 mm,三导洞法分别为-27.93 mm和-28.94 mm,数值相差不大但三导洞法对大跨段的影响更小。采用中导洞法左右洞拱脚水平位移分别为13.69 mm和-14.28 mm,三导洞法分别为10.78 mm和-12.13 mm,三导洞法施工有利于控制隧道的周边收敛。(2)相比三导洞法,中导洞法左右洞拱顶围岩应力差更大,施工偏压问题更明显。(3)两种方法均能满足施工要求,但三导洞法更有利于控制隧道周边收敛,且对大跨段影响较小。In order to optimize the construction method of shallow buried loess bifurcation tunnel,the stress and deformation characteristics of bifurcation are analyzed by using the middle pilot tunnel method and the three pilot tunnel method based on Baishi No.2 Tunnel.The results show that:(1)due to the influence of construction process transformation,the vault settlement at the bifurcation and the horizontal displacement of the arch foot have complex trends.After excavation,the vault settlement of the left and right holes of the middle pilot tunnel method is-28.62 mm and-29.95 mm,respectively,and the three pilot tunnel method is-27.93 mm and-28.94 mm,respectively,the values are not much different,but the latter method has less impact on long-span section.The horizontal displacement of the arch foot of the left and right holes is 13.69 mm and-14.28 mm respectively by the middle pilot hole method,and 10.78 mm and-12.13 mm respectively by the three pilot hole method.The construction of the three pilot hole method is beneficial to control the surrounding convergence of the tunnel.(2)Compared with the three pilot tunnel method,the stress difference between the surrounding rock of the left and right vaults of the middle pilot tunnel method is larger,and the construction bias problem is more obvious.(3)Both methods can meet the construction requirements,but the three pilot tunnel method is more conducive to controlling the convergence around the tunnel,and has little effect on the large-span section.

关 键 词：黄土地区 浅埋 分岔隧道 施工优化 

分 类 号：U455.4[建筑科学—桥梁与隧道工程] U451[交通运输工程—道路与铁道工程]