Analytical Study of the Wide Sleepers on Asphalt Trackbed in Consideration of Nonlinear Contact Condition

摘要

Recent years, domestic and international interest towards high-speed railway increases dramatically. As a consequence, researchers have shown interested on the track types and upper structure of railway too. Currently, generally used roadbed structure utilizes classical track. This structure has shown drawbacks including increased maintenance costs, train operation/run-ability at high speed, and decrease of passenger comfort. Therefore, many researches were conducted in order to overcome these challenges, by developing a concrete track structure, and asphalt trackbed system. The objective of current study was to evaluate the applicability of developed materials for an asphalt trackbed structure. Frictional force at the attached boundary between the developed asphalt materials and upper concrete slab were assessed for performance evaluation. In the end, nonlinear contact model was developed, according to the result from performance evaluation. A wide sleeper for the actual asphalt trackbed was also designed using a developed non-linear attachment boundary model. Then, the structural safety evaluation was performed at HL-25 train load (the design load). In the case of HL-25 design load, RC wide sleepers showed a limitation on usability due to the tensile stress occurred in the lower part of the slab from the interaction with the asphalt trackbed. PC sleepers, with improved lower part tensile stress using a PC tendon, showed relatively stable structural behavior.