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Prevention and Rectification of Rail Joint Defects

2019-11-01 16:34


Prevention and Rectification of Rail Joint Defects

1.1 Fix the rail to avoid crawling that possibly leads to widening of rail gap

Fasten all the bolts to the correct torsion as requested in concrete rail ties; while eliminate all the floating track spikes and complete related crawling proof devices.

1.2 Strengthen tamping to the rail ties at the rail joints

Strengthen tamping to the rail ties at the rail joints, i.e.raise 3~5mm to the 6 rail ties to maintain the abundance and solidity of ballast bed, and replace ground ballast in a timely manner. Model type and material of rail ties at the rail joints must be in consistency with spacing conforming to the regulation. Uniform thickness and consistency in material shall be guaranteed during placing and removing of wear-resistant pad to secure the even force load of the rail ties.

1.3 Guarantee good drainage

Guarantee good drainage of the subgrade to avoid permanent deformation. Timely ballast cleaning and replacement should be conducted when the ballast bed is dirty at the rail joints to avoid hardening and loss of resilience. Guarantee the initial flatness of the rail joints and eliminate unaligned joint ends.


2. Rectification of defects of rail joints

Careful analysis should be made to find correct solutions for defects of rail joints. As concluded from experience, the following approaches can be taken as effective solutions: Welding, replacement, bedding, tamping and ballast cleaning to solve the problem essentially.

2.1 Welding

Welding of faulted part of rail is the most commonly adopted remedy in railway maintenance with focus on repair of chipping on rail joints to prolong the service life of rails.

2.2 Replacement

After inspection of rails, clamping plates and other related facilities, replacement work has to be done to the rails with severe damage or of really poor quality. It should be noted that the quality of the material of the replacement should be guaranteed and in good conjunction with the original rail joint.

2.3 Bedding

It is obviously demonstrated from the damage to the rail joints that subsidence would occur in many cases for which bedding will work efficiently in settlement of such problems and thus is widely adopted with very good effect.

First, plate bedding; second, sand bedding

2.4 Tamping

Replace the original ballast at the rail joints with new one that fits well. Fasten all the bolts tight before tamping, and conduct tamping work beginning from the middle of rail to the end to compact the ballast towards the rail joints.

2.5 Ballast cleaning

Conduct ballast cleaning to the bottom of ballast bed at the rail joint with half remained. Make correct spacing between rail ties before ballast cleaning to guarantee uniform force loading and tamp 3~4 times after lining and lifting of rails till stability is achieved.