Causes and Effects for Creep of Rails

When the train is running, the longitudinal force acting on the rail is often generated to make the rail move longitudinally, and sometimes even drive the sleeper to move together. This longitudinal movement is called creep of rails. The creep of rails is a common disease of railway lines. The creep of rails has a common rule, that is, the two rails of the line always have a tendency to creep in the opposite direction. If left rail to creep forward, right rail to creep back. Linear and curved sections, as well as wooden sleeper and concrete sleeper lines, have similar phenomena. Compared with the concrete sleeper railroad line, the wooden sleeper railroad line is more likely to creep, and the two sections of the sleeper will also creep with the two rails together.

Creep of rails often results in uneven size of gap between railway track and even rail dislocation in severe cases. At the same time, the sleeper will also occur skew phenomenon, which will cause great damage to the line, resulting in poor rail structure and endangering traffic safety. Therefore, effective measures must be taken to prevent the creep of rail.

Causes and Effects for Creep of Rails

The main factors that produce the orbital creep force are the following points.

• Longitudinal force of train gravity on the slope.
• Braking force produced by stopping to slow down a train.
• The temperature force generated by the influence of temperature changes and the tensile force caused by the distortion of the rail under the dynamic load of the wheel.
• Longitudinal horizontal force produced by wave-shaped deflection of rail under rolling dynamic load of wheel.

Rail creep does a lot of damage to the track. The size of gaps in railway tracks is distributed evenly. Due to creep of rails, gap between railway track at one end gradually deforms until it disappears and even expands the rail. The gap between railway track at the other end are stretched, causing fishplate bolts to be pulled or broken. This causes the sleeper to rotate to form the deviation, causes the track to sink and not smooth, produces the low joint and so on disease.

How to Prevent the Creep of Rail

1.Strengthen the anti-creep resistance between sleeper and ballast bed

It is necessary to ensure that the thickness of the ballast below the sleeper is sufficient, the ballast at both ends of the sleeper is wide enough to strengthen the tamping. Carry out railroad maintenance regularly, keep the railroad line smooth, tamp down the ballast bed. In addition, the serious dirty ballast bed should be cleaned to prevent slurry and mud from boiling and bottom climbing to reduce the longitudinal resistance of the line.

2.Add anti-creeping equipment such as rail anchor

Rail anchor is a kind of equipment which can effectively prevent longitudinal displacement of rail. Installation of rail anchor can effectively improve the quality of railway lines and ensure traffic safety, and will greatly reduce the cost of rail creep and maintenance, thereby reducing the cost of railway transportation.

3.Keep the clamping force of rail fasteners

In order to increase the resistance between rail and fishplate, rail and rail tie plate, rail tie plate and railway sleeper, the bolts should be tightened in time, floating track spikes and fasteners should be tightened. For damaged spikes and fasteners, they should be replaced and refurbished in time.