超浅埋隧道下穿铁路引起变形敏感度数值分析

Numerical Analysis of the Sensitivity of Deformation Caused by a Super Shallow-Buried Tunnel Passing under an Existing Railway

南京地铁4号线仙林湖—桦墅站超浅埋区间隧道下穿江南水泥厂专用铁路线,对地表变形控制要求较高。该地段岩溶较为发育,岩性较差,施工存在较大风险。文章结合隧道下穿既有铁路现场地质及施工情况,应用ABAQUS软件建立分析模型,针对土体注浆加固前后、有无路基荷载、是否考虑路基荷载作用间歇性等情况下隧道施工引起的地表沉降及路基变形进行研究,并将分析结果与监测数据进行比较。研究结果表明,本文数值分析结果正确,同时验证了本工程采用的施工工艺能保证工程稳定性,可为类似工程提供参考。

The super shallow-buried running tunnel between Xianlinhu station and Huashu station of Nanjing subway line 4 passes under the dedicated railway of the Jiangnan Cement Plant, and the requirements for ground deformation control are relatively high. The karst is developed and the lithology is unfavorable at this section, and it causes great risks during construction. Based on the actual geological and construction conditions, an analysis model was established using ABAQUS to study the surface settlement and subgrade deformation caused by tunnel construction under two eases： the subgrade load and intermittent function of the subgrade load are considered and not eonsidered before and after the grouting reinforcement of the soil mass. A comparison was carried out regarding the analysis results and monitoring data. The results show that the numerical analysis results are correct and the eon- struction technology guarantees smooth construction of this project.