Research On Key Technology Of Permanent Welding Repair For Serious Damaged Line Of High-Speed Railway

This paper mainly studies the key technology of permanent welding repair, used to rePair the high-speed railway. First we used YHGQ-1200 gas pressure welding rail car doing type inspection on Goubangzi rail welding base, debugging the welding process parameters that is suitable for high-speed railway. After then, according to the railway online locking welding test which was carried out at Qinghai-Tibet railway in August 2013, we did some improvement on the basis of the patent A construction method for welding and heat treatment on one machine of online railway lock welding (Patent application number: 201310698927.2), and proposed the construction method "Sequential online welding".Two welded joint are finished online, and the welding rail car has to climb for welding twice. Then we bending the rail to connect it into the line, using the function of the welding rail car that can tensile weld and lock railway by once, and the key technology of the permanent welding repair for serious damaged line of high-speed railway is preliminarily accomplished.We carried out simulation tests in Goubangzi rail welding base in August 2014, and formulated the time control table for the construction process through the test. Then we did drop test on some of the welded joint and tracked online service welded joint, and the result of drop test is good, online service welded joint has not found any problem yet. This is enough to show that the use of the technology of welding repair for the serious damaged railway line is feasible. At the same time through the construction process control table shows that theoretically within 3 hours of the skylight time that the work of the permanent welding repair for serious damaged line of high speed railway can be completed.After three-day’s simulation test in Goubangzi rail welding base we found that, when welding rail car climbed and operated online using the existing I-type metal sleeper pads would lead to instability of its car body, which is not safe. So we did some improvement on the basis of I-type metal sleeper pads, which we called it II-type metal sleeper pads, and we used it in the construction test of thewelding repair for intercity high-speed railway between Changchun to Jilin. The phenomenon that the welding rail car’s body is not steady in its operation process has been resolved. Then, we put forward a construction method named "offline welding and online welding that is operate in inverted order". One of the joint will be moved to the offline to welding first, then the welding rail car returned out of workspace. After shore up the rail, the welding rail car climbed to the line welded another joint with stress.The whole process spent time on shore up the railand climb welding only once, which greatly improved work efficiency, and shorten the working time.This can ensure the completion of welding repair within skylights time.On the other hand, in Goubangzi rail welding base simulation test the temperature of locking the rail would restore to the original state line. If the original line of rail locking temperature is not standardized, the line will be a security risk after welding repair. After optimization, in the construction test of thewelding repair for intercity high-speed railway between Changchun to Jilin we redesign the rail locking temperature in accordance with the requirements of high-speed railway, and put forward a concept "the amount of overlap" and its formula, making the rail locking temperature more standard, which can ensure the safety of train online.Finally, through theoretical research, data calculation and service feedback of the online joints, we assess the feasibility of the technology of welding repair. Shooting the test procedure of welding repair and editingit into instructional videos.Through the instructional videos will present the key technology of the permanent welding repair for serious damaged line of high-speed railway, and combine with the theoretical exploration of this paper, and play a role in guiding the late work of the permanent welding repair for serious damaged line of high-speed railway.