宁和城际矿山法隧道下穿国铁隧道影响分析

Analysis on Influence of Construction of Mining Tunnel on Nanjing-Hexian Inter-city Railway Crossing Underneath Existing Freight Railway Tunnel

为验证矿山法隧道设计的合理性和下穿货运铁路隧道的安全性,采用数值模拟方法,对宁和城际矿山法区间下穿宁芜货运铁路隧道的影响进行了研究分析。结果表明,区间隧道施工完成后,宁芜货运铁路隧道的最大沉降为6.7 mm,最大水平位移为1.2mm,引起的最大附加弯矩为32 k N·m,变形值满足货运铁路的运营要求,内力值也在结构的设计范围内。说明定向管棚+超前小导管的地层加固措施是可行的,矿山法隧道下穿铁路的设计是合理的,可为类似工程提供参考。

The influence of the construction of a mining tunnel on Nanjing-Hexian inter-city railway crossing underneath an existing Nanjing-Wuhu freight railway tunnel is analyzed by means of numerical simulation,so as to verify the rationality of the design of the mining tunnel and the safety of the existing freight railway tunnel.The results show that, after the construction of the mining tunnel,the maximum settlement of the existing railway tunnel is 6.7 mm,the maximum horizontal displacement of the existing railway tunnel is 1 .2 mm and the maximum additional bending moment induced is 32 kN＆#183;m.The deformation values can meet the operation requirements of the existing freight railway and the internal forces are within the design scope of the structures.It is verified that the ground reinforcement measures including “directional pipe-roof ＋forepoling”taken are reliable,and the design of the mining tunnel crossing underneath the existing railway tunnel is rational.The paper can provide reference for similar projects in the future.