Line Shape Analysis and Dynamic Response of Ballastless Track during Jacking Rectification Fixing

Area of Science:

• Civil Engineering
• Railway Engineering
• Geotechnical Engineering

Background:

• Ballastless track structures are crucial for modern railways.
• Jacking rectification is a key maintenance technique for these structures.
• Understanding track deformation and dynamic response during jacking is essential for safety and efficiency.

Purpose of the Study:

• To investigate the deformation and dynamic response of CRTS II slab ballastless track during jacking rectification.
• To analyze the influence of jacking force and connection modes on track behavior.
• To establish critical jacking force limits and recommend train speed restrictions.

Main Methods:

• A three-dimensional finite element model of the CRTS II ballastless track on subgrade was developed.
• Analysis of line deformation and local damage rules under jacking force.
• Comparison of dynamic responses for different base plate-subgrade connection modes and train speeds.

Main Results:

• Jacking force and dissociation length have minimal impact on deviation.
• Critical jacking force limits are identified: <375 kN (single-point) and <275 kN (multi-point, 5-slab length).
• Maximum lateral deviation reached approximately 22.11 mm under multi-point jacking.

Conclusions:

• Train speeds should be restricted to 150 km/h during jacking without temporary restraint.
• Temporary restraints allow for potential speed increases.
• Findings provide a theoretical basis for ballastless track deviation correction.