Study On Mechanical Properties Of Ballast Rubber Cured Ballast Bed

Ballast glue solidified ballast bed is a relatively stable new form of ballast bed formed by bonding granular ballast together with ballast bonding technology.Ballast glue solidified ballast bed can enhance the stability of the track and has broad development prospects.However,due to the novel form of ballast bed and the late start of the research,the research on it has not been completed.In the actual application process,traditional full-section bonding is mostly adopted,which leads to problems such as too large bonding area,inability to carry out later maintenance after curing and difficulty in removal after damage.According to the application characteristics of ballast glue curing ballast bed,this paper explores the influence of bonding area,ballast glue usage ratio and ballast particle gradation on the mechanical characteristics of ballast glue curing ballast bed.The main research contents include:(1)The discrete element method is used to study and explore the cement-cured ballast bed in Track ballast,and EDEM discrete element simulation platform is used for simulation calculation.As the Track ballast cement solidified track bed is formed by stacking and bonding granular Track ballast,the external contour shape of Track ballast granules has certain influence on its bonding effect.In this paper,the three-dimensional reconstruction method is used to reconstruct the geometric shape of particles,and a more real Track ballast particle structure is obtained.According to the relevant regulations in the national "Code for Design of Railway Tracks",a complete model of Track ballast cement solidified track bed is established in EDEM discrete element software through bonding model.(2)In order to verify the accuracy and authenticity of the model,the vertical stiffness of the real bonded ballast is tested,and the simulation tests under the same conditions are compared and analyzed to verify the authenticity and feasibility of the simulation model.At the same time,the relevant parameters of the model are optimized and adjusted to improve the authenticity and accuracy of the simulation results.(3)Using the simulation model of Track ballast cement-cured ballast bed,the simulation test research is carried out on the bonding area,bonding strength and Track ballast gradation of the ballast bed which affect the mechanical properties of Track ballast cement-cured ballast bed.Finally,the wide-graded Track ballast and polyurethane Track ballast glue with A:B=3:2 ratio in the Track ballast cement cured ballast bed are obtained,which is more conducive to improving the mechanical properties of the ballast bed.At the same time,the influence of bonding area on the mechanical properties of cement-cured ballast bed is analyzed.On the premise of not affecting normal tamping and other maintenance operations,a bonding scheme for stabilizing ballast bed and ballastless-ballastless transition section is proposed.This study has certain practical significance for the construction and construction of Track ballast cement-cured track bed,a new type of track bed structure.