Mechanical Analysis And Cracking Behavior Of Asphalt Concrete Pavement On Steel Bridge Deck

The deck pavement of steel bridge often produces cracks,ruts and other diseases.Asphalt concrete is laid on orthotropic steel plate,the stress of bridge deck pavement is very complex,and there are many influencing factors,so it is necessary to study.In this paper in view of the steel bridge deck pavement diseases,using ANSYS finite element software,finite element theory and the theory of fracture mechanics,the mechanical properties and cracking behavior of the surfacing layer was studied,for bridge deck pavement design and maintenance are proposed.First,the specific analysis of asphalt concrete paving layer on orthotropic panel is carried out.The disease of bridge deck pavement and its causes are analyzed.And according to the causes of disease puts forward the steel bridge deck bridge panel maximum vertical displacement index,the maximum tensile stress in pavement layer control indicators,surfacing,maximum shear stress,pavement's vertical displacement and temperature stress of pavement layer index of 5 control index,and gives the selection method of different temperature control index.Secondly,the ANSYS finite element model is established with a certain bridge in China as the engineering background.The effects of different pavement thickness,elastic modulus of different pavement layer,vertical and horizontal load and overweight on mechanical properties of pavement layer were studied.The results show that the maximum vertical displacement of the steel bridge panel as index,the most unfavorable load steel bridge panel horizontal position from distance road center line 12.75 m to12.75 m,vertical to horizontal clapboard,and suggested the transverse width for temporary parking.Taking maximum tensile stress and shear stress as control indicators,the most unfavorable load position of the pavement layer on the bridge surface is horizontally above the middle of two u-shaped ribs,and the longitudinal load is directly above the middle of two transverse partitions.According to the stress analysis results,it is recommended that the thickness of the upper layer is between 40 mm and 45 mm,the lower layer is between 30 mm and 35 mm,and the total thickness of the paving layer is between 7cm and 8cm.It is recommended that the elastic modulus of the lower layer is between 1600 Mpa and 2100 Mpa,and the upper layer is between 1000 Mpa and1500Mpa.Finally,established the 3 d ANSYS finite element model of the deck surfacingfracture,through interaction integral method to study the different load location,different crack depth,different pavement layer thickness and modulus of elasticity,vertical and horizontal load and the changing rule of the stress intensity factor under overload conditions.The results show that the crack depth,pavement thickness,elastic modulus increase will make stress intensity factor increases,the horizontal load of a smaller effect on stress intensity factor overloading can make the stress intensity factor of linear increase,and according to the results of the analysis of the surfacing layer is given after cracking engineering maintenance advice.