Deformation Characteristics and Unloading Time for Passenger-Dedicated Railway Surcharge Preloaded Subgrade

Analytical design of surcharge preloading schemes on soft soils were performed using the deformation characteristics corresponding to several surcharge preloading tests. To ascertain the reliability of this technique, investigative data were collected during the construction of a passenger dedicated railway line in China to deduce the design specifications and control standards. This was done by establishing an unloading time equation based on regression curve fitting method of the measured data; given that different types of settlement deformation gives corresponding unloading time calculations. Specific methods for the calculation of surcharge preloading and unloading time point for passengers dedicated line in the railway sector were also examined. Finally, measured data from the Wuhan-Guangzhou passenger line surcharge preloaded embankment were used to verify the design validity and reliability. The predicted results matched with the settlement deformation trend and the post-construction settlement strictly meet with the control standards.