Vibration of different types of tracks of subway in soft soil

The settlement of subway tunnel due to the rail load after its construction has cause wide concern. But the report of dynamic characteristics of railroad considering uneven settlement has not been reported. Based on a subway tunnel in Zhejiang Province, by choosings two sections of the tunnel, the settlement deformation is measured and the vertical vibration of iron rails is tested. The differences of tunnel settlement deformation and rail vibration are analyzed based on the results. The optimization analysis is conducted for the two section styles. The research results show that the calculated values by the theoretical model agree with the measured ones. But the theoretical results are less than the measured ones because it does not consider the uneven settlement and bending effect. The rail vibration level of steel spring floating slab track is 10 dB smaller than that of the ordinary monolithic track. The vibration acceleration of steel spring floating slab track rail reaches the peak value earlier when the car arrives and quells down later when the car leaves because the inherent frequency of the former is lower than the later one. The vibration of ordinary monolithic track affects the surrounding soil stronger than the vibration of steel spring floating slab track. Larger bigger settlement will cause larger vibration. In order to ensure good operation conditions, it is suggested that the rail track style should adopt steel spring floating slab track in soft soil districts with uneven settlement.