Research On Dynamic Mechanic Properties Of Pavements Based On Roughness Index

Because of the low level of pavement roughness,the running vehicles will apply dynamic loads to the pavements.This can explain why there are so many differences between the results calculated from the static loading model and that in the actual conditions.Therefore the characteristics obtained from static loading model are not able to describe the dynamic characteristics of the actual pavement structures.For the object of the IRI,this paper analyzed the interaction between vehicles and roads.What's more,an additional load due to the interaction between vehicle and road is considered.On this basis,the loading form of dynamic load is determined.This paper established the three-dimensional finite element model,and analyzed the dynamic characteristics of pavement structures by using the software ABAQUS.The main research contents of this paper are as follows:(1)The vehicle dynamic load which is divided into two parts(static load and additional load)is converted into a series of sine wave functions with varying amplitude.Through the dynamic load coefficient,the static load and the vehicle additional dynamic load are linked,and the vehicle load expression is obtained.(2)The three-dimensional finite element numerical analytical model is established by using the finite element software ABAQUS,which is based on the assumption of multilayer elastic system.Besides,this paper simulated the dynamic response of asphalt pavement structure(including dynamic displacement,dynamic stress,dynamic strain,dynamic shear stress,etc.)under dynamic loads.Through comprehensive analysis,the damage rule and mechanism of pavement structures under random loading are analyzed.On the other side,the dynamic response(flexual stress)of concrete pavements which is based on the assumption of elastic foundation plate is simulated and analyzed(including dynamic force of concrete,dynamic strain,dynamic stress of subgrade,dynamic force of the bottom for concrete,etc.).