Mapping Relation between Rail and Bridge Deformation Considering Nonlinear Contact of Interlayer

Area of Science:

• Civil Engineering
• Railway Engineering
• Structural Mechanics

Background:

• High-speed railways rely on advanced track structures for safety and performance.
• Ballastless track structures, particularly slab types, are increasingly common.
• Understanding structural deformation effects is crucial for track longevity.

Purpose of the Study:

• To investigate the impact of structural deformation on high-speed railway slab-type ballastless tracks.
• To analyze the relationship between girder and rail deformation under various conditions.
• To evaluate the influence of key parameters on track deformation and potential failure modes.

Main Methods:

• Utilized the principle of stationary potential energy to develop a theoretical model.
• Mapped the relationship between girder vertical deformation and rail deformation.
• Verified the theoretical model using finite element analysis and experimental data.
• Analyzed the effects of parameters like deformation amplitude, mortar layer modulus, and fastener stiffness.

Main Results:

• Consideration of nonlinear interlayer contact revealed significant track slab disengagement near beam joints.
• Track slab disengagement was most pronounced adjacent to deformed beam sections.
• Nonlinear relationships were observed between girder deflection amplitude and track deformation, fastener forces, and slab disengagement length.
• Increased fastener stiffness and mortar layer elastic modulus led to monotonic, nonlinear increases in fastener force and slab disengagement length.

Conclusions:

• Nonlinear contact significantly influences track slab behavior, leading to disengagement near joints.
• Parameter variations, particularly girder deflection and component stiffness, have complex, nonlinear effects on track performance.
• Findings highlight potential adverse impacts on the lifespan and safety of high-speed railway track structures.