Research On Side Wear Prediction And Mitigation Measures For Heavy-haul Railway

Heavy-haul transportation is an inevitable trend in the adjustment of long-distance cargo transportation mode,and is the best measure to enhance transportation efficiency.It is an important symbol for China's railway to achieve leap-forward development.Due to the limitation of terrain and other factors,China's heavy-haul railway lines have many small radius curves.Numerous small radius curves will aggravate the interaction between the wheel and rail,making the wheel and rail wear problem particularly prominent.According to the relevant data,about 98% of the outer rails on the small radius curve of China's heavy-haul railway are scrapped due to the side wear exceeding the standard set standard.Based on this,this paper will establish a predictive model that can reliably predict the development of rail side grinding and apply the model to study the influence of orbital parameters and operating conditions on the development of rail side grinding,in order to find a way to slow the development of rail side grinding through reasonable parameter design.The measures and research results will provide theoretical basis and reference for the relevant departments to maintain the normal operation of the railway.It is of great practical significance to extend the service time of the railway,reduce the heavy-haul transportation cost and improve the efficiency of heavy-haul transportation.In this paper,based on the domestic and foreign scholars' prediction models and methods for rail wear and some measures to slow down the development of rail wear,the paper focuses on the side-grinding problem of heavy-haul trucks in the operation process.The railway line was measured and obtained a large amount of data.Based on the non-elliptical wheel-rail contact theory and the improved Archard material wear model,a truck-track coupling dynamics model was proposed and applied to simulate an existing heavy-haul railway line.The development of the side rail side grinding is compared with the measured side friction value of the heavy rail to verify the accuracy of the model.Finally,by changing some orbital parameters in the truck-track coupling dynamics model,the development law of side rail grinding under heavy-haul railways is studied in detail,and some corresponding measures are proposed to slow the development of rail side grinding,in order to repair the railways for relevant departments.Provide theoretical basis and reference.The results show:(1)For the condition of the curve radius of 500 m and the driving speed of 65km/h,the gauge distance is 1440 mm,and the gauge length is 5mm,which will help to slow the development of rail side wear.Under other working conditions,in order to slow the development of rail side wear,the gauge distance can be appropriately widened,and the widening value depends on the specific situation.(2)In a certain range,the 1:40 rail bottom slope of the left and right rails will help to slow the development of rail side wear.(3)The development rate of rail side wear increases with the increase of super high,and compared with the equilibrium super high,the under-high condition will be beneficial to the slowing of the rail side wear.According to the specific conditions of the curve line,in the case of the curve condition,in order to slow the development of the rail side wear,the super high can be set to the under-high.(4)the radius of the curve of the railway curve can be constructed as large as possible,at least not less than 800 m,in order to slow the development of the side grinding of the rail,as the case permits.(5)Therefore,frequent lubrication of the rail can greatly reduce the rate of development of the rail side grinding.It is recommended to install the rail lubrication device at the outer rail position of the small radius curve to ensure that the wheel-rail friction coefficient is not higher than 0.3.