| With the development of China’s transportation,the construction projects of mountain roads are increasing year by year in order to promote economic exchanges between different regions.However,some limit indexes are inevitably adopted due to the complex topography and high engineering cost,mountain roads form long and long longitudinal slope sections.The long and steep road section is difficult to construct,the speed of vehicles and the operation state of drivers will be greatly affected during the driving process,and the braking frequency is far higher than that of the ordinary road section.The road surface has high frequency and deep degree of disease,so it is difficult to ensure the driving safety.Therefore,it is necessary to study the asphalt pavement of the long and long longitudinal slope section.Firstly,define long and longitudinal slope based on safety and pavement diseases,conduct on-site investigations of pavement diseases and safety accidents on long longitudinal sections of mountain roads,summarize the characteristics of diseases and hidden dangers of safety accidents,and theoretically analyze the cause of long and long longitudinal slope disease and the demand of pavement skid resistance.Secondly,the dynamic load model is constructed by using the finite element method to simulate the stress of the pavement structure of the long and long longitudinal slope road section under the influence of four factors: slope,axle load,temperature and vehicle speed.Through the analysis of the change rule of the mechanical indexes such as displacement,compressive stress-strain and shear stress-strain under the action of various factors,the disease of the long and long longitudinal slope asphalt pavement is obtained mechanism.Thirdly,aiming at the actual road demand of asphalt pavement on long longitudinal slope sections,by comparing and analyzing the characteristics of existing anti-skid surface gradation types,it is proposed to increase the specifications and specific gravity of coarse aggregate particle size in AC-13 median gradation,and then carry out anti-skid grade with design.Through rutting test,trabecular bending test,submerged Marshall test,freeze-thaw splitting test,anti-skid performance test,the road performance of the mixture is comprehensively analyzed to obtain the effect of changing the coarse aggregate specifications and specific gravity on the road performance.Based on the entropy-TOPSIS,the anti-skid grade with the best comprehensive road performance is determined.Then,based on the fractal theory,different graded mixtures are analyzed to obtain different graded fractal dimension values and structural characteristics.And based on different gradation fractal dimension values and road performance test results,functional models of fractal dimension value,dynamic stability,maximum bending strain,residual stability,freeze-thaw split strength ratio,pendulum value,and structural depth were established to establish the range of fractal dimension of asphalt mixture in gradation design.Finally,by summarizing the key technologies in the construction phase of asphalt pavement,the construction technology of anti-skid asphalt pavement on the long and longitudinal slope section of mountain road was proposed based on the test road.And the whole life cycle analysis of the economic and social benefits of the construction and operation stage of anti-skid pavement on the long longitudinal slope section was carried out,and the anti-skid pavement had good social and economic benefits.The application of the results not only saves construction costs,but also improves the anti-skid ability of asphalt pavement on long and longitudinal slope sections,reduces the hidden dangers of accidents on dangerous sections,and reflects the people-oriented construction concept. |
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