Research On Management Value Of Track Geometric Irregular Speed Limit Under 30t Axle Load

With the rapid development of the economy and society,the demand for railway transportation in China has increased year by year.In recent years,heavy-haul transportation technology has developed rapidly,but the contradiction between increasing transportation demand and limited transportation capacity has not been completely solved.There are two main ways to improve the transportation capacity.One is increasing the number of trains to increase the driving density.The second is increasing the axle load of heavy-haul trucks.China’s typical heavy-haul railways include Daqin Railway,Shuohuang Railway and Wari Railway.Among them,the Shuohuang and Daqin Railways mainly operate 25 t axle-load trucks.In recent years,some 27 t or 30 t axle-load trucks have been operated.The axle-load is 30 t.Increasing the axle-load will inevitably increase the daily maintenance and repair work of the railway engineering department.The operation of the large axle-load trucks also increased the track structure deformation and rail wear,accelerates the deterioration of the track geometry,and thus affects the train operation safety.However,China does not currently have maintenance maintenance standards for 30 t axle-load conditions.The Shuohuang Railway and the Wari Railway,which have already started the 30 t axle-load truck,are still carrying out routine maintenance and repairs based on the existing Railway Line Repair Rules.For the general-purpose railway,which is mixed with passengers and cargoes,the Shuohuang Railway is a complete coal-only line.Certain provisions of the existing rules are obviously not suitable for the Shuohuang Railway and the Wari Railway,so the 30 t axle-load condition is established.Track irregularity IV speed limit management value is particularly important.This paper analyzes and summarizes the research status of the orbital irregularity management value at home and abroad,and combines the two methods of detecting track irregularity at home and abroad to compare and analyze the difference of the management values of the track irregularity at home and abroad,and considers the inertial reference method relative to the string measurement method.More advantage.On this basis,combined with the influence of track irregularity on the dynamic performance of the truck,the safety evaluation index and allowable limit of the wheel-rail dynamic performance are reasonably determined.The model of 30 t axle-load KM96 aluminum alloy hopper car and 25 t axle-load C80 gondola was established by SIMPACK multi-body dynamics simulation software.The single-wave harmonic excitation displacement input function method was used to track geometry.The simulation is not smooth;the rationality of the model is verified by combining the measured track performance of the following railway lines with the measured track irregularity of the Huanghuang Railway.The paper analyzes and calculates the dynamic mechanical response of the two models of the empty car and the heavy car at different wavelengths of the straight curve,and determines the most unfavorable wavelength of each type of track irregularity;after determining the most unfavorable wavelength,combined with the field irregularity detection mode Study and analyze the influence of the track irregularity amplitude on the wheel-rail dynamics,compare and analyze the calculation results under different amplitudes to find the main control indicators of each local irregularity and the IV-level speed limit management values,and carry out the existing norms at home and abroad.