葛洲坝坝顶铁路是永久性铁路。由于工程的需要,坝顶尚需通行汽车。因此位于2号、3号船闸上的桥梁需要公路铁路并用的桥面(图1),又因通航净空的要求而设计为活动桥.此两座活动桥为垂直升降式,过船时将桥升起。桥梁降到坝面高程,在不通行火车时,可通行汽车。 Gezhouba dam top railway is a permanent railway. Due to the needs of the project, the dam top still needs traffic. Therefore, the bridges on the No.2 and No.3 locks need to be used as the bridge deck for the highway and railways (Figure 1), which is designed as a movable bridge because of the requirements of navigable clearance. The two movable bridges are vertical lift type, rising. Bridge down dam surface elevation, in the absence of access to the train, you can pass the car.