过江隧道穿越既有铁路相互影响研究

过江隧道穿越既有铁路的相互影响是一个难点.依托重庆长江隧道穿越襄渝铁路工程进行研究,研究结果表明：过江隧道施工对既有铁路两个方向地表沉降的影响都很小,最大值为2.549 mm,故受影响的既有铁路附近地层不需做特殊加固处理,但要加强监控;既有铁路对过江隧道结构安全性及洞周位移影响也较小,在列车荷载作用下结构最小安全系数为6.8,过江隧道结构仍是偏于安全的,故隧道结构可不作加固处理,只需加强监控.研究成果为保证既有铁路的正常运营及过江隧道的结构安全性提供了理论基础,并可为相似工程提供参考.

Research on Interaction of River-crossing Tunnel across Existing Rails

The interaction of river-crossing tunnel across existing rails is a difficult point. Research in the interaction based on project of Yan- gtze river tunnel across Xiangfan-Chongqing railway in Chougqing shows that ： 1. The construction of river-crossing tunnel has little effect on ground settlement of existing railways in both directions. The maximum value of ground settlement is 2. 549 ram. Therefore ,the affected strata in the vicinity of existing rails do not need to do special reinforcement treatment, but it is necessary to strengthen monitoring measurement. 2. The existing rails has little effect on structural safety and convergence of tunnel inner perimeter of river-crossing tunnel. The minimum safety factor of tunnel structure under train loading is 6. g. The structure of river-crossing tunnel is still simply safe. So, the tunnel structure does not need to do reinforcement treatment, but it just need strengthen monitoring measurement. Research results provide theoretical basis to ensure the normal operation of existing rails and structural safety of river-crossing tunnel. And it will provide references to other similar projects.