Research On Loosen Sleeper Effect And Maintance Method Of Twin-Block Track

Recently,high-speed railway construction is developing fast,meanwhile,there are some problems occurring on the track structure.The research on Sui-Yu Zheng-Xi and Wu-Guang high-speed railway shows that several circumstances take place on the double-block nonballasted railway, such as,cracks on the contact surface between prefabricate sleeper and cast-in-situ roadbed slab, spalling of roadbed slab concrete, sleeper looseness. This paper based on the sleeper looseness of the double-block nonballasted railway, applies the vehicle-track vertical coupling dynamics theory and utilize the finite element dynamic simulation analysis software ANSYS/LS-DYNA to establish the vehicle-double-block nonballasted track-subgrade vertical dynamics analysis model and the collision finite model between sleeper and roadbed slab and the restorative materials static model,which are used to carry on the dynamic and static respond research of the double-block nonballasted sleeper systematically.Firstly,some reasonable simplification should be conducted based on the structure character of the sleeper-loosed track system using the nolinear spring to simulate the loose sleeper to establish the vehicle-double-block nonballasted track-subgrade vertical dynamics model to carry on the research about the comfort and safety effect of traveling on the loose sleeper.Secondly, the collision finite model between sleeper and roadbed slab established through the software ANSYS/LS-DYNA is used to calculate the impact effect from the loose sleeper to roadbed slab and the mechanical effect from the loose sleeper to the adjacent sleeper under the condition of train load.Then,based on the establishment of the static solid model,the theoretical simulation is conducted on the loose sleeper filled with restorative materials to do some researches including the mechanical property of restorative materials and surrounding roadbed slab under the condition of train load and temperature load, physical mechanical property of the loose sleeper restorative materials, specific material parameters.Finally,the dynamic property of the track structure when sleeper loosens is tested in situ and get a theoretical result,which is compared with the test result on the Sui-Yu nonballasted railway when sleeper loosens.The comparation proves the calculation result reasonable.Additionally,the research of the nonballasted railway repair methods and reference at home and abroad are gathered to clear up repair methods of the double-block nonballasted railway when sleeper loosens.