Studies On Dowel Bar Mechanics Performance Of Pavement Based On Impact Loading

Cement concrete pavement is generally used in our country’s airport.In order to reduce the inner stress caused by temperature change,seems used be setting in corresponding position.So the seam become weak part of the pavement.Under the long term effect of outer load,the joint may appear subsidence,fault and other diseases that affect normal use.It seems that the testing and evaluation of joint load transfer ability play a very important role on cement concrete pavement surface maintenance and prolong service life.The FWD equipment is usually used to test the joint load transfer capacity,But it exist many disadvantages such as inconvenient transportation equipment,low efficiency of loading and so on.To solve these deficiencies,this paper proposes to use the vehicle impact load instead of the FWD equipment thus to reflect the joint load transfer ability by vibration characteristics of pavement.The research content are as follows:1.Through the analysis of different simulation pavement smoothness method and finally selects the trigonometric function synthesis simulation to generate the different levels of pavement.2.a quarter vehicle model is selected to simulate the vehicle impact load according to the research question and analyzes the influence law of impact coefficient by the different vehicle velocity,different pavement roughness under different vehicle jump height.3.Three-dimensional entity model that consider contact between dowel bar and concrete is established by ABAQUS.Dowel bar parameters and structure parameters are considered to analysis joint load transfer coefficient and displacement difference.4.The impact vehicle load is applied on the finite element model.Extracted the acceleration signal in MATLAB to make spectrum analysis and get the frequency,amplitude,phase difference of the pavement.The law of vibration characteristics of the pavement by dowel bar parameters and structure layer parameters is discussed.The relation between load transfer coefficient and vibration amplitude ratio,phase difference are established.It provides a new method for the load transfer ability evaluation5.The cement concrete pavement outdoor model was established based on the similarity theory.load transfer coefficient under static load and amplitude ratio under Impact load are obtained to verify the feasibility of using amplitude ratio to evaluation load transfer coefficient.