Adaptability Assessment And Strengthening Technology Research Of Dabao Heavy Haul Railway Track Structure

Foreign transportation practical experience shows that increasing the axle load can significantly improve the transport efficiency,and the axle load of foreign heavy haul railway trains is mostly concentrated in 28-32.5 tons,with the maximum reaching 40 tons.China's first electrified Daqin heavy haul railway coal line,through continuous expansion technology transformation,the transport volume significantly increases year by year,mainly operates 25 tons of axle load of 10000 to 20000 tons of heavy haul trains,and volume has reached 400 million tons.The Dabao line was electrified from2007 to 2009.Subsequenly,the special freight truck with 25 tons of axle load and 80 tons of load was mainly used,and in 2010 the volume has exceeded 200 million tons.the increase of axle load and length of freight train correspondingly increases the force and frequency of action on the line infrastructure,which makes the structural stress,deformation,fatigue performance and so on change greatly.With the continuous increase of Dabao line annual traffic volume,and the track structure diseases gradually increase,especially after the operation of heavy haul trains with ten thousand tons,the occurrence and development of track structure damages are rapidly accelerated,and the rail fatigue damages,loose fasteners,frog cracks,joint diseases and so on show a rapid growth trend.Although the track structure does not lose the use function in the short term,with the acceleration of deterioration speed,there is still a problem that whether its long-term performance meets the requirements of heavy freight.Therefore,it is urgent to study the long-term adaptability of the railway track structure to the heavy-haul freight trains.In this paper,based on the domestic and foreign research results of heavy haul railway track structure,the adaptability evaluation and strengthening technology research of Dabao line railway track structure are carried out.Firstly,the paper introduces the development of heavy haul railway transportation and the research status of track structure at home and abroad.Secondly,the paper analyzes the status quo of the track structure and the law of track component damage of the Dabao heavy haul railway line,and grasps the degree of deterioration and the actual operation state.Then,studies the track structure adaptability and security issues,analyzes the influence of heavy haulfreight train on track structure,uses a series of methods and means of the quasi static calculation,dynamic test,prediction of weibull distribution probability of serious rail injury,vehicle-mounted GPR detection and so on,and assesses the adaptability problem of rail,sleeper fastener,ballast bed,and turnout.Finally,the paper puts forward four aspects of track structure integral reinforcement measures: the reinforcement technology of rail and rail joint,strengthening selection of sleeper fastener,the stability strengthening of the curve track bed,and turnout structure optimization,fully improves the carrying capacity of track,makes the track equipment often keep a good state,solves some new problems which the axle load increase and the volume increase brings,puts forward the proposal of Dabao line track structure strengthening test,and makes the long-term performance of track structure meet the requirement of the heavy haul freight.Through adaptability evaluation and reinforcement technology research of Dabao heavy haul railway track structure,the paper masters the mechanism of heavy haul train acting on the track structure and the damage law of railway track components,effectively reduces the wheel-rail force,fully improves the strength of track structure,prolongs the service life of the track components,provides a theoretical basis and technical support for the establishment of perfect maintenance system,and has important guiding significance to guarantee railway transport safety.