Optimization Of Port Road Pavement Structure Based On Traffic Survey And Rutting Prediction

With the development of economy,the quantity of import and export goods in port area increases,which leads to the rapid increase of the number of heavy-duty vehicles transporting goods on the dredging roads in port area and the widespread overload and overweight situation.Some of the original pavement structures can not meet such heavy traffic tasks,resulting in a large number of diseases on the dredging roads.As an important link in the construction of the "one belt and one port" port,the expansion of the port scale and the construction of the transport network of Qingdao port are all very important.Therefore,it is necessary to investigate and analyze the traffic characteristics,pavement structure and pavement disease characteristics of the dredging road,and put forward the pavement structure combination suitable for the dredging road according to the investigation and analysis results.First of all,this paper investigates traffic characteristics and diseases of dredging roads.The survey found that the proportion of heavy-duty vehicles on the dredging roads was more than 30%,and the proportion of overloaded vehicles was more than 80%.Heavy vehicle concentrated travel and overload problem lead to low vehicle speed on roads.The full load ratio of the vehicle is not only the same.According to the investigation on the diseases of the dredging roads,it is found that the main diseases of the dredging roads are the ruts under the wheel tracks.Through the investigation and analysis of in situ core drilling sampling of road rutting,it is found that the deformation of the upper layer of the road is larger.In this paper,the pavement structure of dredging roads is recommended for traffic characteristics and disease characteristics of dredging?Secondly,the dynamic modulus test,rutting test and uniaxial penetration strength test are carried out for the asphalt mixture used in the original pavement structure and the high modulus asphalt mixture and the large diameter permeable asphalt mixture used for the rutting of the dredging road.The dynamic modulus and phase angle of asphalt mixture are obtained by experiment,and the dynamic modulus of asphalt mixture under high temperature is analyzed.High modulus asphalt mixture still has high dynamic modulus under high temperature conditions,indicating that it has good high temperature performance and deformation resistance.The results of rutting test show that the dynamic stability of asphalt mixture decreases with the increase of tire pressure and the rutting deformation increases,which indicates that overloading has a significant effect on the dynamic stability and rutting deformation of asphalt mixture.The decrease of dynamic stability and the increase of rutting deformation of high modulus asphalt mixture are relatively low,which indicates that it has good dynamic stability and rutting resistance.The shear strength of each asphalt mixture is analyzed by uniaxial penetration strength.The results show that the shear strength of high modulus asphalt mixture is obviously improved.Thirdly,the mechanical response of the proposed dredging pavement structure under different axle loads at room temperature and high temperature is analyzed by finite element method.From the point of view of vertical shear stress and shear strain in asphalt layer,the recommended dredging pavement structure has good rutting resistance.From the point of view of transverse tensile stress and transverse tensile strain at the bottom of asphalt layer,the recommended dredging pavement structure.Finally,the rutting prediction model based on shear stress is modified and calibrated.The rut prediction model is used to calculate the development of recommended pavement structure.The results show that the high modulus asphalt mixture can effectively improve the high temperature rut resistance of pavement structure.Through the fatigue life calculation and analysis,it can be seen that the large size of permeable asphalt mixture can effectively improve the fatigue resistance of asphalt layer.Finally,a pavement structure combination suitable for heavy haul traffic is recommended.