Monitoring and Numerical Study of Long-Term Settlement of Track Bed with Sparse Pile Foundation for Tram

Abstract:

The track bed with sparse pile foundation was developed to avoid the excessive settlement of track beds due to long-term cyclic wheel-pressure. To understand the settlement development， a two-year monitoring of an actual tram project in a southern city in China was reported. The results reveal that the settlement of the track bed increased rapidly in the initial stage. The settlement gradually reduced after around one year and tends to be stable after two years. Moreover， based on the explicit cumulative strain model， an equivalent finite element method is proposed for predicting the long-term cumulative settlement of the track bed with sparse pile foundation. A good agreement between the monitored and calculated results demonstrates the rationality. Furthermore， discussions on the bearing mechanism of the track bed with sparse pile foundation are presented.