重载铁路隧道内铺设Ⅲa型轨枕及宽枕条件下隧底动力特性

Dynamic Characteristics of Tunnel Bottom with Laying TypeⅢa Sleepers and Wide Sleepers in Heavy Haul Railway Tunnels

针对一座铁路隧道基底结构出现翻浆冒泥病害,建立了动力学数值模型,分析C80货车以时速100 km通过分别铺设Ⅲa型轨枕、宽枕的隧道时,隧底有无病害工况下的结构动力特性。结果表明:对于填充层上表面最大动压应力,Ⅲa型轨枕隧底无病害工况>Ⅲa型轨枕隧底有病害工况>宽枕隧底无病害工况>宽枕隧底有病害工况;隧底有病害工况,无论铺设Ⅲa型轨枕还是宽枕,仰拱底面动拉应力均较无病害工况大50%左右,填充层上表面及仰拱底面的动变形均较无病害工况大40%左右;有病害工况填充层上表面、仰拱底面最大振动加速度较无病害工况分别大约78.6%~82.9%、27.7%~36.5%。总体而言,C80货车通过铺设宽枕隧道时,隧底结构的动力性能要优于铺设Ⅲa型轨枕。

A dynamic analysis model was established to analyze the dynamic characteristics of the railway tunnel when a C80 type freight train traversing at a speed of 100 km/h with laying TypeⅢa sleepers and wide sleeper,based on the occurrence of slurry and mud defects in the foundation structure of tunnel.The results show that,the max dynamic compressive stress of the upper surface of filling layer shows a trend ofⅢa sleepers without defects>Ⅲa sleepers with defects>wide sleepers without defects>wide sleepers with defects.Whether layingⅢa sleepers or wide sleepers,the dynamic tensile stress on the bottom of inverted arch with defects is significantly higher than that without defects by about 50%,and the dynamic deformations of the upper surface of filling layer and the bottom of inverted arch with defects are significantly greater than that without defects by about 40%,the surface vibration acceleration of the upper surface of filling layer and the bottom of inverted arch with defects is significantly higher than that without defects by about 78.6%~82.9%,27.7%~36.5%respectively.Overall,the dynamic characteristics laying wide sleepers in the tunnel is better than that layingⅢa sleepers.