Assessment of Structural Safety and Dynamic Stability for Pile-supported Slab Track on Soft Soil

초록

For the ballastless track on soft soil, subsidence restraint or reduction is necessary to guarantee the running stability of high speed train and the maintenance of track systems. Construction of some bridges and replacement methods for soft soil are to be an alternative for settlement free of the ballastless track, but economic feasibility of these methods is being questioned. Recently pile-supported slab track has been constructed as the solution to subsidence of concrete slab track on soft soil in Europe and China. Pile-supported slab track is composed of piles, cross-beams, platforms and concrete slab track. In this paper, for a study on the domestic application of non-buried pile-supported slab track, two types of pile supported slab track are assumed and quasi-static analysis for two cases is conducted. Then sectional design is conducted using moments, shear forces and axial forces as results of analysis. In addition, natural frequency analysis and time history analysis are conducted to assess the dynamic performance of pile-supported slab track such as vertical deflection at midspan, maximum vertical velocity and dynamic amplification factor related to running stability and riding quality. From results of static/dynamic analysis and sectional design, pile-supported slab track is structurally safe and dynamically stable.