铁路隧道仰拱结构振动特性实测分析

摘要

为研究隧道仰拱及仰拱填充结构的振动特性,以兰新高铁福川隧道为依托进行现场测试,分析不同运行速度列车振动荷载作用下,不同深度处仰拱及仰拱填充结构的振动加速度和动应力响应及衰减规律,并通过数值模拟进行对比分析.结果表明:列车速度一定时,列车运行侧仰拱及仰拱填充中振动加速度响应随着深度的增加逐渐减小,双线同时行车时,振动加速度响应相比单线行车时有所提高,且提高的幅度与行车速度有关,数值模拟得到的结果与实测结果基本吻合.仰拱及仰拱填充是承载振动加速度的主要载体,应将其作为结构设计的重点.研究成果对优化隧道支护体系确保列车运行安全具有重要意义.%In order to study the vibration characteristics of tunnel invert and tunnel invert filling,in-situ train induced vibration tests were performed in the second railway line of Lanzhou-Xinjiang.Attenuation and distribution laws of the vertical vibration acceleration in the tunnel invert and tunnel invert filling under different speeds and depths were Analyzed,and compared the results with numerical simulations.The analytical results indicate that with the certain speed,the vertical vibration acceleration response value decreases with the depth in a fast attenuation rate on the trains running side.The vertical vibration acceleration response value increases when the train running on double lines at the same time compare with running on a single line.Increased degree is related to the train running speeds.Numerical simulation results agree well with field tests results.Tunnel invert and its filling are the main carriers of bearing vibration acceleration,which should be the key point in design.The results have important significance for optimizing the supporting system of tunnel and ensuring train running safety.