复杂山区隧道浅埋洞口段施工方案优化研究  

Research on Optimization of Construction Scheme for Shallow Buried Tunnel Entrance Section in Complex Mountainous Areas

作　　者：贾卫东 JIA Weidong(China Railway 14th Bureau Group Co.Ltd.,Jinan Shandong 250000,China)

机构地区：[1]中铁十四局集团有限公司,山东济南250000

出　　处：《铁道建筑技术》2025年第3期154-157,204,共5页Railway Construction Technology

基　　金：中铁十四局集团有限公司科研课题(91370001630559891202238)。

摘　　要：为优化复杂山区隧道浅埋洞口段施工方案,依托某隧道工程,原施工方案(φ108管棚+三台阶法)无法有效控制变形,故优化为拱盖法施工,并通过数值模拟与现场监测验证其适用性。结果表明:施工方案现场出现多处裂缝与破坏,变形量值大且增长快,并且数值模拟结果显示,变形在拱顶与拱腰较大,应力在拱顶位置集中,表明原施工方案无法维持隧道稳定;优化施工方案采用拱盖法后隧道与地表变形及结构受力大幅减小,对拱顶抑制效果明显;拱盖受力变形集中于拱顶、拱腰与托梁,表现为拱顶下沉两端翘起;对拱盖拱顶厚度与高度进行优化,最终确定拱盖最佳厚度与高度为0.65 m与9.5 m。在原拱盖法基础上减小支护施作步距并加强隧道变形监测与反馈,现场施工与变形情况良好,同时地表变形较小,收敛较快,验证了拱盖法现场适用性。In order to optimize the construction plan for the shallow buried entrance section of a tunnel in complex mountainous areas,a certain tunnel project was used as a basis.The original construction plan(φ108 pipe shed+three-bench method)failed to effectively control deformation,thus it was optimized to the arch cover method for construction.Its applicability was verified through numerical simulation and on-site monitoring.The results show that the original plan uses a 108 pipe shed,which results in multiple cracks and damages on site,with large and rapidly increasing deformation values.Numerical simulation results also show that the deformation is larger at the arch crown and waist,and the stress is concentrated at the crown position,indicating that the original construction plan could not maintain the stability of the tunnel.After optimizing the construction plan and adopting the arch cover method,the deformation and structural stress of the tunnel and surface are significantly reduced,and the suppression effect on the arch crown is obvious.The deformation of the arch cover is concentrated on the arch crown,arch waist,and support beams,manifested as the arch crown sinking and the two ends lifting up.The thickness and height of the arch cover are optimized,and the optimal thickness and height of the arch cover are finally determined to be 0.65 m and 9.5 m.On the basis of the original arch cover method,reducing the support construction step distance and strengthening tunnel deformation monitoring and feedback,the on-site construction and deformation situation are good,and the surface deformation is small and converges quickly,verifying the applicability of the arch cover method on site.

关 键 词：拱盖法施工 隧道洞口 施工方案 方案优化 数值模拟 

分 类 号：U455.4[建筑科学—桥梁与隧道工程]