Study On The Surfacing Fatigue Test Of Steel Bridge Deck Based On The Heavy Load Conditions

Bridge is an important transport hub which undertake an important function of cross-river,se and canal.In recent years,with the improvement of highway infrastructure and the transport industry,the road carrying heavy vehicles gradually increased.At the same time more and more car are overload.Overloading phenomenon will accelerate the disease of the steel deck pavement system and reduce the fatigue life Considering the problems above,the actual vehicle of the Fourth Nanjing Yangtze River Bridge is need to be obtained.The theory analysis and numerical simulation and experimental study are used in this study to establish the fatigue damage model and study the fatigue damage life of surfacing.Firstly,according to the data recording of the Fourth Nanjing Yangtze River Bridge's Axis ID,the study analysis the overloading condition of the bridge deck and the load characteristics of the vehicle.The study put forward tire grounding area and tire ground pressure distribution that suited for overloading analysis.The stress characteristic of the bridge pavement under the action of different loads and different modulus ratio are ascertained by the ABAQUS finite element calculation.It also ascertains the relationship between the most unfavorable load position and elasticity modulus.Secondly,in this study,based on the damage mechanics principle,the fatigue damage evolution law of double layer asphalt mixture paving system on steel bridge deck was analyzed from the perspective of mechanical approximation.Also the prediction formulas of damage field,stress-strain relationship and fatigue life of the paving system were proposed.Fatigue tests of compound beams prepared at paving layer construction site of the Fourth Nanjing Yangtze River Bridge were used to validate the reliability of established model.Thirdly,compound beams prepared at paving layer construction site of Nanjing fourth Yangtze river bridge were studied by indoor fatigue test.The correlation parameters that demanded in the fatigue damage model can be obtained by the test and then the fatigue life of the compound beams can be predicted.The reliability of established model can be validated by comparing the outcome predicted and experimental results.Fourthly,establishing finite element model of composite beam,the top surface tension strain of different loads and different modulus ratio.The fatigue damage life under the actual vehicle load of the Fourth Nanjing Yangtze River Bridge can be obtained by the equivalent replacement of top surface tension strain between Composite beam experimental results and the finite element model results.