Prevention And Treatment Of Rail Joint Defects

The prevention and treatment of rail joint diseases start from the following aspects:
(1) Strengthen the maintenance and fastening of rail joint parts and fasteners. Including rail joints, it is necessary to maintain a reasonable rail joint value at all times; regularly inspect and retighten high-strength bolts, and keep the torque of joint bolts above 500N·m; apply oil to splints and joint bolts to reduce the impact damage of the train; If the standard is exceeded, the rail joints and sleeper fasteners can be repeatedly fastened in spring and autumn after the rail joints have been well prepared.
(2) Rational lifting and tamping operations. Since rail joints are subjected to repeated impact loads from trains, the stress and vibration acceleration of the ballast bed at the joints are much higher than those at the non-joint parts, so the joint ballast bed should have good tamping quality. When lifting the joint, the rail surface should be raised flat and then tamped on all sides, and the joint should not be raised to form a bulge. Especially for the insulating joints with low buckles, we first need to clean the ballast bed once, replace and replenish new ballast, then reverse the splints of the joints, and replace the insulating joints (especially the insulation of the two grooves in the middle) with new ones. If the insulating material fails, tighten the bolts of the fastener joints to eliminate the high and low teeth of the insulating joints, and then perform eight-sided tamping.
(3) Regulate the ballast bed at the joint. The hardening of the rail joint track bed not only significantly reduces the bearing capacity, but also greatly increases the line stiffness, reduces vibration reduction and vibration isolation performance, and intensifies the residual deformation of the line and the development of various diseases. Use the skylight repair to clean the bottom and replace the new ballast. Adjust the ballast gradation at the joint, carefully select the ballast, replace it with 20-40mm small gravel within the 5-hole range of the joint, and strengthen eight-sided tamping, so that the train load transmitted through the rails and sleepers is even Distributed to the roadbed through the ballast bed.
(4) Repair the rail surface. Uneven wear and loss of rail ends, scratches are the huge additional impact of rail joints on rolling stock during operation, which aggravates line deformation and leads to further development of diseases. The joint rail surface must be repaired, polished and welded in time. Frequently ask the road patrol workers to observe whether they meet the standard every day and replace them in time.
(5) Improve the elasticity of the cushion under the rail. After many years of operation of the elastic cushion under the rail, the rubber backing plate will gradually harden, especially the backing plate at the joint part under the action of strong impact force. The elasticity gradually decreases, and the backing plates of the four sleepers in the joint area should be replaced in time to restore the good elasticity of the track structure.
(6) Joint maintenance must be strengthened, especially for lines that have just been mechanically cleaned: ① Keep the geometric state of the joint track in good condition; Ashes, coal ash, ash, and sand, dust, and external loose substances brought in by the wind should be cleaned and screened in time; ③The saddle shape should be polished in time, the buckle should be bowed, and the rails at the joints should be welded to keep the rail surface smooth. ; After the welding repair, use a 1m long ruler to check that the height of the welding repair part does not exceed 0.5mm. After grinding and grinding, the rail surface is flat, smooth and uniform.

(7) Dealing with the wrong teeth of the rail: ①For the high and low wrong teeth on the rail surface, the first method can be used on both sides of the rail, and two pieces of the wrong teeth can be used to pad the plywood at the low rail end and the lower jaw of the rail, or on the high side The bottom of the rail on both sides of the rail and the plywood are padded with wrong tooth pieces for rectification. The other is to loosen the joint and loosen the horizontal pad of the joint plywood pad, and then tighten the joint bolts and fasteners after padding. If the high and low teeth are serious, you can use the above methods to eliminate them. ②For the left and right teeth, you can solve it by padding a piece of wrong teeth, or by padding double-layer spring washers and other washers. The above operations of tightening the joint bolts must be tightened while playing splints to tighten the joints.
(8) Treatment of the fat edge of the rail: because there is a rail joint at the rail joint, and this place is a weak point of the line, the impact of the train wheel at this place is large, and the rail joint is easy to cause crushing, which makes the rail head become larger and the working edge It is easy to have a small section of rail fat edge and other parts are not, so that the gauge is seriously unsatisfactory, which will easily affect the performance of the rail inspection car and dynamic multi-passenger. It is also one of the main factors that artificially feel the car shaking. It should be timely Grind with an angle grinder or chop off with a chopstick. The fat edges of other parts should also be polished in time with a grinder.
(9) Keep the position of the joint sleepers correct, and the distance between sleepers must be calculated and set according to the number of configured pieces. If there is any skew, the skylight should be used to repair the square sleeper.

(10) For the treatment of branch nozzle diseases, I think that it can be carried out by reversing the splint or replacing two splints, diverting and bending the track. Reversing the splint is because the rail joint is limited by the factory process of the splint and the centrifugal force generated when the train passes on the small radius curve causes the branch or joint to be in bad direction, and the hard bend of the rail and the splint is formed after a long time. Reversing the splint in the skylight point can make the splint form a triangular corner by hard bending the splint The tooth piece is placed between the splint and the rail in the middle of the joint). If not, use the large nylon seat to divert and correct the direction. According to the degree of the nozzle, appropriately increase the width of the outer ballast bed, and ram the beat in layers to increase the resistance of the ballast bed. Replace the inner and outer splints at the splint, and use the reverse bending of the splint to control the joint splint. At the same time, in the operation of channel diversion, the nozzle joint can only be pressed, not picked. If it is necessary to pick up, use the method of moving the small waist to drive the joint, do not directly touch the joint to prevent the expansion of the nozzle.
Of course: in order to eliminate rail joint defects, laying seamless lines is the best solution.