Research on the characteristics of water in the sleeper void of double-block ballastless track

According to the investigation and survey of the service condition of the double-block ballastless track in China, the breakage rate in the rich rainfall areas or the poor drainage lots of double-block ballastless track runs much faster than the dry areas. Some typical diseases, such as sleeper loose, contact loss between sleeper and roadbed slab, will lead to water still in the sleeper void. Free water underneath the sleepers would become dynamic water with certain pressure and flow rate under the high speed and high frequency action of train loads. Dynamic water is able to accelerate crack growth rate and scour the bonding interfaces between sleeper and roadbed slab([1,2]), affecting the safety,durability and riding quality of track structure. It is meaningful for us to research on sleeper loose of double-block ballastless track under the coupling action of train load and dynamic water and prove the mechanism of sleeper loose in double-block ballastless track under action of dynamic water. Calculating the value of water pressure and velocity of flow and then providing references for study on the hydrodynamic characteristics.