Mechanical Response Of CA Mortar Layer Void Damage To CRTS ? Type Ballastless Slab Track System

With the gradual development of China's railway industry,the problem of cement emulsified asphalt mortar voiding in operation and maintenance has gradually become a research issue of scholars.As the leveling layer of the track system,CA mortar plays an important mechanical role.CA mortar has been in a complex environment for a long time.Under various external loads,it is inevitable that damage and void will occur.In this paper,the model of CRTS I slab ballastless track-roadbed for high-speed railway vehicle is established by using ABAQUS software.The voiding state of CA mortar is simulated by using life and death element method.The static and dynamic state of CRTS I slab ballastless track system is preliminarily explored under the varying conditions of void length,void width,void height and driving speed of CA mortar.The main research contents and conclusions are as follows:(1)Establish a high-speed railway vehicle CRTS I type ballastless track-subgrade model through the large-scale finite element software ABAQUS.Taking track irregularity into account,the China track spectrum is selected as the track spectrum of the model.The correctness and feasibility of the model are verified by comparing the measured data of dynamic test results of ballastless track on Suiyu Railway.(2)The void state of CA mortar was simulated by the method of life and death unit.The static and dynamic responses of CA mortar void to ballastless track system are analyzed by numerical simulation of void length,void width,void height and traveling speed under static and dynamic conditions respectively.(3)Under static analysis,when the void width is greater than 2m,the void length is greater than 1m,and the void height is greater than 30mm,the rail slab may crack.(4)Under dynamic analysis,when the void width and height are at the extreme value,the driving speed is greater than 250 km/h and the void length is greater than 1.5 m.The vertical displacement of the rail will exceed the allowable limit.When the driving speed is more than 300 km/h and the void length is more than 2m,the wheel load reduction rate is close to 0.9,which has the risk of derailment,The maximum tensile stress of the Track slab plate exceeds the specifications and is prone to cracks.When the driving speed is over 300 km/h,passengers have a poor ride experience with the change of the void size.