Study On The Accident Mechanism And Safety Control Of Large Bus In The Combination Section Of Curve And Slope

With the continuous improvement of China’s highway transportation system and the convenience of highway passenger transport,the proportion of highway passenger transport in transportation is increasing,and the total passenger transport is increasing.However,while highway passenger transport brings convenience to passengers,the number of bus accidents in highway transportation is also increasing.Large buses have large passenger capacity,large volume and high centroid,and are prone to sideslip or rollover accidents in the combination section of curve and slope,which seriously affects the road traffic safety.The coupling effect of wind,rain and snow increases the risk of accidents.This paper analyzes the risk factors of large-scale bus in the combined section of curve and slope under the action of bad weather,analyzes the stress of large-scale bus operation characteristics in the combined section of curve and slope,studies the mechanism of large-scale bus sideslip and rollover traffic accident,and establishes the model based on cross wind speed,passenger capacity,height of mass center,operation speed and road roundness Combined with trucksim simulation test,the paper puts forward the threshold of sideslip and rollover of large bus in different road conditions of curved slope combination section,which provides a theoretical basis for the setting of safety assurance measures of large bus in curved slope combination section,so as to improve the safety of large bus in curved slope combination section Operation safety level.The main research contents are as follows:This paper studies and analyzes the risk factors of the operation of large-scale passenger cars in the combination section of curve and slope,including the four aspects of people,vehicles,roads and environment.Among them,the risk factors that have the greatest impact on the driving safety of large buses include the driver’s own factors,bus running speed,road type and bad weather factors.The driver’s own driving experience and reaction ability can make the driver choose to operate the bus correctly in the face of complex road conditions to avoid accidents;when the large bus runs too fast,it is easy to cause traffic accidents due to the limitation of the driver and the bus itself;when the large bus runs on complex road sections,especially the sections with poor curve slope combination When encountering the bad weather of wind,rain and snow,the driver’s sight is blocked,and the road adhesion coefficient is reduced.When the coupling effect of these risk factors,it is easier for the large bus to cause sideslip,rollover and other accidents.The investigation and analysis of the running speed of large-scale bus on the curve slope combination section provides data support for the virtual simulation test and analysis of the sideslip and rollover of large-scale bus on the curve slope combination section under the action of adverse weather.Based on the theory of vehicle aerodynamic characteristics,the six component aerodynamic force of large bus is studied,and the influence of the six component aerodynamic force on the operation safety of large bus is analyzed.Aerodynamic drag will increase the fuel volume of the bus and reduce the dynamic performance of the bus;aerodynamic lift and pitch moment will reduce the adhesion between the tire and road surface of the bus;roll moment,lateral force and yaw moment will affect the lateral stability of the bus.In this paper,the stress analysis of the operation characteristics of the large-scale bus on the curve slope combination section is carried out,and the mechanism of the sideslip and rollover accidents of the large-scale bus is studied.The operation safety mechanical model of the large-scale bus is established based on the cross wind speed,passenger capacity,centroid height,operation speed,radius of the highway circular curve,superelevation,longitudinal slope,road adhesion coefficient and other parameters.By using the virtual simulation software of trucksim,the bus model,road model,cross wind model and driver model are established.The simulation model of the bus running on the curve and slope combination section under the coupling effect of adverse weather is established through different road line index and road condition.Taking the lateral acceleration,lateral offset and tire vertical load of large bus exceeding a certain limit value as the limit state value of sideslip and rollover of large bus,the threshold values of sideslip and rollover under different linear indexes and road conditions are obtained,which can provide reference for the operation safety of large bus on curved slope combination section.This paper puts forward the safety control measures for the operation of large-scale passenger cars in the curved slope combination section,improves the operation safety of large-scale passenger cars in the curved slope combination section,reduces the occurrence of traffic accidents,reduces the safety loss of passengers’ life and property,and improves the safety of China’s highway transportation.