Stress Analysis Of Deck Pavement Of Prefabricated Simple-supported Bridge Under Vehicle Load

Prefabricated structure is widely used in engineering for medium and small span bridges,but a large number of engineering practices show that this type of bridge’s deck pavement is prone to damage.Different from other types of bridge structures,the transverse connection of the assembled bridge will weaken under the long-term action of vehicle load,which makes the deformation of the transverse main beams of the bridge unsynchronized under the action of moving load.At the same time,the repeated alternating stress and unsynchronized deformation in the pavement will also aggravate the problem of stress concentration in the pavement,which makes the bridge deck pavement more prone to damage accumulation and disease.However,most of the researches on the problems of bridge deck pavement diseases focus on the relationship between the stress of the pavement layer under static load and the bearing limit of the material.Therefore,with the support of Transportation Science and Technology Plan Project of Henan Province," Study on Damage Mechanism and Control Technology of Simply Supported Structure under VehicleBridge Coupling Vibration",this paper studied the stress response characteristics of the pavement layer of the Shahe Bridge under moving load,analyzed the stress distribution characteristics and influencing factors of the pavement layer of this type of bridge under moving load,and discussed the reasons for the failure of the deck pavement.The main contents are as follows:(1)The stress response and distribution characteristics of the pavement under different lateral loading conditions under uniaxial loading are compared and analyzed.The analysis results show that pavement stress is very sensitive to T-beam flange thickness,and the pavement layer above the connection position of the main beam flange is more susceptible to tensile failure than other positions.Also,the adhesive layer under the wheel is more prone to shear failure than other locations,which is mainly caused by the shear stress along longitudinal direction of the bridge under the moving load.(2)Based on the moving load characteristics and structural characteristics of prefabricated simple-supported beam bridges,this paper analyzed the influence of the number of axial loads,horizontal forces,and the failure of the diaphragm on the mechanical properties of the pavement.The results show that the increase of axle load will increase the compressive stress along the axial direction of the bridge in the pavement layer and the shear stress along the horizontal direction of the bridge in the bonding layer,the existence of horizontal force along the axial direction of the bridge will increase the compressive stress along the bridge in the pavement layer and the shear stress along the bridge in the bonding layer significantly,and the diaphragm can effectively reduce the probability of tensile failure of the pavement layer and shear failure of the bonding layer.(3)The influencing factors of pavement diseases under moving load were studied.It is found that the peak normal stress of the pavement layer and the peak shear stress of the bongding layer is negatively correlated with the speed and span,and positively correlated with the overload.