Design Of Porous Asphalt Pavement System For Urban Road Intersection

With the continuous development of transportation technology in our country,along with the development of the concept named "sponge city",the porous asphalt pavement is more and more used in urban road new construction or maintenance projects.In view of the characteristics of serious channelization of urban road traffic,slow speed,frequent start-up and braking of vehicles,the discrete element software PFC3 D was appied to establish a virtual test of rutting for drainage asphalt pavement.According to the built virtual rutting test,the rutting resistance of porous asphalt pavement was studied in this paper.as well as making a detailed study and discussion on the design and application of porous asphalt pavement system in urban road intersection area.Firstly,the discrete element simulation of asphalt mixture for urban road intersection porous asphalt pavement was investigated.The image prosessing technology and 3D modeling technology were used to establish a three dimensional(3D)aggregate model library,and the asphalt mixture was simulated by using the model library.After virtual compaction and parameter assignment,a 3D digital model of porous pavement with stable structure was generated.Secondly,after obtaining the digital test piece of porous asphalt pavement,an experimental method of virtual rutting test was carried out.The reliability of the method was verified by comparing with the indoor rutting test.In addition,the results of the virtual rutting test of different graded test pieces were compared and analyzed,the influence of aggregate gradation and environmental temperature on the rutting resistance of porous asphalt mixture was discussed.Thirdly,an optimization experimental method of rutting test was proposed by taking braking force into consideration.After the analysis and discussion of the stress response of the pavement structure under the braking load,the curve of the internal stress of the pavement structure with the depth under the braking load was obtained,and the position of the maximum deformation was predicted.After the virtual rutting test based on the braking force,the influence of aggregate gradation on the deformation of the specimen plate under the braking force was discussed,the feasibility of the test method was verified,and the recommended gradation of the porous asphalt pavement at the urban road intersection was proposed.Finally,after completing the mixture ratio design of porous asphalt mixture,the pavement drainage structure of urban road intersection was designed.By means of numerical simulation,the seepage analysis of porous asphalt pavement model under rainfall condition was carried out,the seepage law of drainage asphalt pavement structure under different rainfall intensity was studied,and the drainage performance of urban road intersection drainage pavement system was analyzed and discussed.In this paper,the drainage system design of the drainage asphalt pavement at urban road intersections and the seepage law of the pavement internal structure were taken as the research object.A virtual rutting test of the drainage asphalt pavement based on the discrete element method was established.The internal structure stress distribution characteristics and rutting resistance performance of the drainage asphalt pavement under the braking load were analyzed.This paper can provide a certain theoretical guide for the optimization of the drainage system design of the drainage asphalt pavement at the urban road intersection.