Study On Some Key Technical Problems Of Transverse Reinforcement Of Assembly Concret Slab Bridge

Assembly concrete slab bridge has been used as the common bridge for the medium and small span bridge in our country because of its advantages of easy fabrication,convenient construction and economy.There are more and more single beam bearing phenomenon in assembly concrete slab bridge with the increasing of traffic volume and service life.Thus how to improve the lateral coordination between slabs has become a hot research.External prestressing transverse reinforcement is a new reinforcement method in recent years,and it is gradually adopted in bridge reinforcement with its advantages of initial low cost,short duration,and good results.However,the reinforcement mechanism is still lack of unified understanding,the simulation of the hinge joint in the reinforcement is relatively rough,and the comparison between the method of reinforcement in engineering examples need to be added.Therefore,some key problems encountered in reinforcement are explored in this paper by means of theoretical analysis and numerical simulation,based on the external transverse prestressing reinforcement.The main work of this papers are as follows:(1)Based on the principle of the hinge-joined plate method,an analytical formula is established to consider the effect of transverse reinforcement;and by means of finite element analysis,change and influence factors about support reaction of each plate are revealed,considering external transverse prestressing reinforcement.(2)The assumption of the traditional sine function is modified by concentrated load which is more close to the actual situation of the wheel load.When calculating transverse load distribution,the correction parameter of stiffness coefficient is offered in the situation where the concentrated load is at the middle of the span.All of these provides a more accurate theoretical basis for practical engineering detection(3)The interface element is used to simulate the damage state of the transverse hinge joint.The initial value and the quantization interval of the relevant parameters in the interface element is calculated by numerical analysis and theoretical deduction of positive and negative.The normal and shear stiffness and the variation between joint crack and fault displacement is obtained.The numerical equation of about normal displacement and tangential displacement and tangential stiffness is fitted.All of these lay the foundation for structural deterioration and reinforcement analysis.Besides,the applicability of the theoretical analysis results is verified by finite element simulation.(4)The experiment of bridge reinforcement is carried out,and the reinforcement effect of external transverse prestressing and steel plate are compared,showing that the former can increase the emergency capacity of hinge joint and the latter is more obvious to improve the transverse load distribution.