Causes of Rail Curve Damage and Remediation Methods

The Causes and Solutions of Poor Curve Direction

 

1. The causes of poor curve direction

(a) Improper dialing method, dialing by experience, with eyes looking at the estimated dialing, often using simple dialing method, will cause the accumulation of errors or bad curve head and wrong direction.

(b) Wrong maintenance method, dialing not combined with the level, high and low remediation, not reserved for the amount of rebound; rail has hard bend, joint wrong teeth, rail bottom slope is not consistent; dialing before not even rail joints; dialing after not timely backfill bed, pounding uneven, etc.

(c) Material failure, decay, sleeper decay, concrete pillow broken, anti-climbing equipment, gauge bar lack, failure, etc. caused by curve direction change.

(d) Roadbed disease: due to improper maintenance and untimely, resulting in roadbed storage water, turning slurry bubble mud, sinking and other phenomena, especially in the bridge and tunnel at both ends of the half-fill half excavation, but also easy to cause slip collapse and other diseases, driving line displacement.

 

2. Rectification of poor direction of the method

(a) To ensure the correct gauge, level. Set ultra-high and gauge widening according to regulations, thoroughly lock the line and prevent crawling. Jiao straight rail hard bend. Replace the wear and tear over the limit of the nail, pad and fasteners, adjust the inappropriate slope of the rail bottom, comprehensive cleaning and sieving unclean road bed, eliminate the turning pulp and mud, strengthen the pounding, eliminate the pits and hanging plate.

(b) Keep the positive vector does not exceed the limit. Seriously do a good job of curve correction calculation and dialing work, dialing, change, pounding organic combination, the entire curve to be fully considered, unified adjustment. The amount of rebound should be reserved appropriately when dialing, more when pressing down, less when picking up, more when dialing large amount, less when dialing small amount. In the phi volume is larger, the traffic is busy lot, can use the dialing method in stages. Each time only dial part, after several dialing to achieve the amount of dialing requirements. When using the dialer, pay attention to pick up the dialer nest, avoid lifting the road, dial after the positive vector should meet the requirements of the "repair rules".

(c) Keep the head and tail of the curve round and smooth. Before investigating and measuring the positive vector at the site, first dial the straight direction of both ends of the curve, eliminate the reverse bend and "goose head", so that the head and tail of the curve back to the correct position, it is best to use the instrument to determine the head and tail of the curve, and then the actual measurement of the positive vector. In the paddle operation, you can drive from the ends of the curve to the middle. In the small radius curve head and tail to maintain a certain thickness and width of the roadbed, and tamp the roadbed, so that the track direction is stable. In addition, reasonably set the length of the easing curve, super high, super high downhill, track gauge widening and decreasing.

(d) Clean up the dirt and keep the roadbed dry. Timely clean up the roadbed on both sides of the waste that hinders the drainage of the roadbed, clean up the drainage equipment, to ensure smooth drainage, to eliminate the roadbed water, slurry, sinking and other diseases, do a good job of bridge and tunnel at both ends of the roadbed protection and reinforcement, to prevent the slope from slipping collapse, so that the line remains solid, stable.

 

The "Goose Head" Curve

 

"Goose Head" is the head or tail of the curve deviates from the appropriate plane position, to the outside of the curve projection, out of the straight line direction, the formation of a small reverse curve, resembling a goose head.

 

1. Reasons of "Goose Head"

The reason for the curve "goose head" is that the straight line near the curve is not in the right direction, the dialing operation of the dialing volume is not planned properly, the visual inspection of the dialing error is large, etc. In the small radius curve, the impact of the train into the head and tail of the curve is larger, the bed transverse resistance is not enough can also produce "goose head".

The curve has a "goose head", the direction is not round and smooth, resulting in rail wear, line shaking, damage to the quality of the line, affecting the safety of traffic. Curve "goose head" disease can be divided into the following kinds of situations.

(a) straight line direction is not the tangential direction of the curve, bias in or bias out of the curve head and tail to produce "goose head".

(b) The head and tail of the curve are not fixed, and the position of the marker stakes is shifted inward or outward, and the straight line is set into a curve or the curve is set into a straight line, producing a "goose head" at the beginning and end of the curve.

(c) Often blindly carry out local positive vector small adjustment, the positive vector to drive together and produce "goose head".

(d) in order to dial the road to save work and effort, a long period of time to pick up, arbitrarily reduce the radius, the positive vector will be concentrated to the straight slow, slow straight point near and produce "goose head".

 

2. Rectify the curve "goose head" method

To prevent and eliminate the curve "goose head" disease, the following methods can be used in conjunction with the specific situation: (a) before the comprehensive adjustment of the site positive vector, first dial the straight direction of both ends of the curve, with visual inspection or simple dialing method to remove the pressure "goose head", and then the actual measurement Then take the actual measurement and calculate the alignment. Under normal circumstances, the original straight line direction should not be changed.

(b) Where there is a "goose head" curve, the easing curve is not good, therefore, the easing curve should be planned according to the provisions of the positive vector, ZH, HY, YH, HZ points fixed in the correct position.

(c)The curve must be dialed with a half dial distance rope positive method after calculating a thorough dialing, to prevent simply to reduce the amount of dialing, without taking into account the original design conditions of the curve, not according to the calculated value of the blind small adjustments, arbitrarily change the positive vector and pick up, down the pressure of the practice.

(d) in order to avoid some errors arising from the dialing operation to one end, can be dialed from the two ends of the curve respectively, gradually dialed to the convergence of the mid-point of the circular curve.

(e) As the site hopes that the curve will be a good whole, first dial the "goose head", and then measure the site positive vector, and then dial the whole curve, this is more time-consuming, at the same time, if the "goose head" is not understood, not only can not eliminate If the "goose head" is not well understood, not only will the "goose head" be eliminated, but also the curve will be set out a long diffuse bend at the end.

 

The Causes of Joint Support Mouth and Remediation Method

 

The reason for the joint support mouth on the curve is due to the elasticity of the rail and hard bending caused by the joint support mouth. This kind of disease mostly occurs in the small radius curve, especially the curve of relative type joint. At the same time, the joint ballast shortage, rail joints bad, etc., will intensify the development of the mouth.

 

2. the method of rectification joint support mouth

(a) the use of toggle to rectify the joint mouth, because the mouth at the toggle, can be used to indirectly affect the method. Such as outward dialing the joint, can dial both sides of the small waist, with a small waist to move the joint outward. If the joint is pivoted inwards, the small waist is moved inwards by pivoting the joint. This can reduce or even eliminate the joint support mouth.

(b) Do not use a hard top at the joint to pivot.

(c) Strengthen the track connection at the spur to control lateral movement of the track.

(d) Widen the bed of the upper strand, fill and ram the ballast of the rail sleeper box, or set up anti-climbing support under the two strands of rails in the rail sleeper box before and after the support mouth, in order to keep the curve stable.