地铁车站下穿既有铁路站场咽喉区的施工方案及防护措施

西安地铁火车站站下穿铁路站场咽喉区,施工难度高。分析了全明挖、分离岛-先隧后站大盾构、分离岛-先隧后站矿山法等三种施工方案。经比选分离岛-先隧后站矿山法施工方案最优。详细介绍了地面铁路股道及岔道加固措施,并阐述了深孔注浆加固地层、大管棚+超前注浆小导管等CRD(交叉中隔墙)法开挖等辅助措施。在项目施工期间,通过自动化监测系统进行全面细监控,并通过协调联动机制共享监控量测信息,针对监测预警信息,及时采取增加垫片及补充道砟等措施,既保证了国有铁路的行车安全,又保证了地铁施工的顺利进行,验证了施工方案的可行性。

Construction Scheme of Subway Station Crossing under the Throat Zone of Railway Yard and Protective Measures

The Railway Station of Xi′an subway is built under-passing the throat area of railway yard with great construction difficulty.Three construction schemes are analyzed and compared,including the full open excavation,the separation island-tunnel before station shielding and the separation island-tunnel before station mining,and the third one proves to be the best through comparison.Then,the reinforcement measures for railway track and turnout are elaborated in detail.Auxiliary measures like the deep hole grouting method is adopted to reinforce the stratum,the large pipe shed+advance grouting small conduit and center cross diagram(CRD)method are used for excavation.During the construction,relying on the automatic monitoring system and through the coordination and linkage mechanism,the forecast information are obtained and analyzed.Measures such as adding gasket and ballast to the railway station track are taken to keep the smooth line operation and meet the traffic safety of national railway.At the same time,the feasibility of the construction scheme is verified.