基于风险源隧道断面优化及加固研究

Study on Optimization and Reinforcement of Cross-Section Based on Risk Source Tunnel

柳条湖站是沈阳地铁10号线重点工程,2号出入口周边环境复杂。车站暗挖段施工长度70.37m,明挖段施工长度21.25m,在暗挖段预留接口。部分暗挖地段位于各类管线下方,施工风险级别高。对于隧道穿越管线的情况,采取改变暗挖断面形式,避免了大规模管线迁移和管线施工风险,故需结合隧道结构受力和施工、使用安全来决定。采用荷载-结构法对改变结构断面进行研究。经计算分析:暗挖段通常采用拱形断面,为了减小断面高度,避免穿越管线风险,可以采用矩形断面,同时也能保证结构的安全性符合要求。采取地面注浆及小导管掌子面背后注浆,加固了隧道上方管线,使管线与土体连接成整体。

Liutiaohu station is the key project of Shenyang Metro Line 10.The surrounding environment of entrance and exit 2 is complex.The construction length of the concealed excavation section of the station is 70.37 m,and the construction length of the open excavation section is 21.25 m,in which the interface is reserved in the concealed excavation section.Some concealed excavation sections are located under various pipelines,and the construction risk level is high.For the situation that the tunnel crosses the pipeline,the form ofconcealed excavation section is changed to avoid the risk of large-scale pipeline migration and pipeline construction.Therefore,it needs to be determined in combination with the stress oftunnel structure and the safety of construction and use.The load structure method is used to study the change of structural section to meet the needs of use.The calculation and analysis show that the arch section is usually used in the concealed excavation section.In order to reduce the section height and avoid the risk of crossing the pipeline,the rectangular section can be used,and the safety of the structure can meet the requirements.The ground grouting and the grouting behind the small conduit face are adopted to strengthen the pipeline above the tunnel and connect the pipeline with the soil as a whole.