track-bed相关论文
For the 30,000 km long French conventional railway lines (94% of the whole network), the train speed is currently limite......
甘肃省引洮总干渠9号隧洞工程出口段底拱混凝土轨道床全长810 m,为C20混凝土;圆弧型混凝土薄壁结构,宽度为3.26 m,半径R=2.905 m,......