Study On Mechanics Analysis Of Asphalt Pavement Based On Local Strain And Estimation For Fatigue Cracked Life

Cracking is an ordinary disease for asphalt Pavement. Cracking will reduce the carrying caPacity of Pavement, and affect the traffic conformability, and accelerate the Pavement damage and shorten service life. Presently the understanding of the fatigue cracked mechanism of asphalt Pavement is fixed. Research on fatigue cracked isn't yet systematical and deep, and it wasn't introduced into any design method of asphalt Pavement, it is necessary to conduct the research to the bituminous pavement weary dehiscence, the analysis bituminous mixture weary characteristic and the bituminous pavement structure stress characteristic, proposes the bituminous pavement weary dehiscence life estimate method, in order to may control the weary dehiscence in the design stage. Like this is advantageous to the consummation bituminous pavement structural design method, the safeguard bituminous pavement operational performance and the service life.Based on the world-wide researches, this paper puts forward the method of forecasting the fatigue cracked life of asphalt pavement with local strain.Calculate the local strain and local stress of asphalt pavement with elastic-plastic finite element method. And compare it with the results calculated by approximation-engineering method to verify its feasibility, through analysis of engineering example and the finite element method,determine the tensile strain threshold value and tensile strain limit value established effective pavement load axis,from the perspective of local strain verified the harm of heavy load and overload,The paper also analysis the influence of parameter variation on local strain of asphalt pavement to provide evidence for asphalt pavement structure design. Parameter conclude load, thickness and modulus of surface course, modulus of base course, thickness and modulus of stress absorbing layer.Based on fracture mechanics theory, the method of calculating the fatigue cracked life of asphalt pavement is put forward.The paper simulates propagation path of fatigue crack and analysis the influencing factors on its propagation life.In addition, based on local strain-theory, testing road entitative engineering and research results, this paper predict fatigue crack initiation life of asphalt pavement,and predict fatigue crack propagation life of asphalt pavement based on fracture mechanics.