Causes of Track Unevenness and Remediation

The gravel track bed is an unstable component of the track structure. Under unstable repeated loads from trains, dynamic elastic deformations and residual accumulation of deformations in the vertical and lateral directions occur. These deformations not only affect the smooth running of trains but also threaten the safety of traffic when they accumulate to a certain limit. In order to keep the line in good condition, the maintenance and repair of the track structure must be carried out regularly.

 

1. Types of Track Irregularities

(1) High and low unevenness: due to the roadbed sinking, the roadbed pounding is not solid and so on causes the rail along the longitudinal direction to produce uneven sinking caused by the front and rear high and low unevenness. In the train power under the action of rail low and pad, pad and rail sleeper and the top surface of the bed will appear between the hanging plate or dark pit, the safety of traffic is extremely unfavorable;

(2) Horizontal unevenness: mainly due to the left and right strand rail sinking amount is not equal to cause;

(3) Triangle pit: within a specified distance, first the left rail is higher than the right rail and then the right rail is higher than the left rail, the height difference exceeds the permissible deviation value and the distance between the two maximum horizontal error points is less than 18 m. Its existence may make the train in a fixed axle before and after the 4 wheels in a momentary load reduction or overhanging serious when it may climb up the rail to endanger the safety of traffic;

(4) Direction is not smooth: refers to straight line is not straight curve is not round. Usually is due to the rail hard bending fasteners loose, and gentle curve downhill and other reasons caused. Poor line direction must cause the train wheel sway left and right to intensify the wheel impact and thus cause other line disease high speed trains are particularly obvious when the serious endanger the safety of traffic;

(5) Compound unevenness: refers to the same position in the rail vertical and horizontal unevenness together superimposed.

 

2. Track Unevenness Remediation Method

(1) The use of large road maintenance machinery operations: section to the construction unit to provide detailed information such as line comprehensive diagram, wiring diagram, curve elements and other machinery according to the above materials to do a good start, dialing tamping and ramming work and each operation after the roadbed power stability and replenishment of ballast replacement damage rubber mat and remove the operation lot to adjust the high mat, road crossing pavement, ballast bridge on the rail protection work;

(2) Diversion work: in the gauge and its rate of change is bad when the diversion work, concrete sleeper line diversion is achieved by adjusting the fasteners or gauge stopper;

(3) Pad work: in the line turnout local high and low level triangle pit deviation is small (not more than 6mm when) start pounding is difficult to achieve the operational requirements when using the track pad. Each place to raise the mat board shall not exceed 3 pieces of total thickness shall not exceed 25mm;

(4) Fastener work: fastener slack will make the rail along the rail sleeper produce local displacement. Requirements often keep the fasteners in tight against the state generally in the pad work the next day to tighten again in the maintenance work before and after are fully tightened fasteners.