The Precast Hollow-cored Slab Bridge Transverse Joint Design And Improvement Methods

Precast hollow slab bridge,with its own advantages,is very common in the small and medium span bridges,and occupies a considerable proportion.However,after investigation,under the comprehensive influence a variety of reasons,the precast hollow slab common disease problems,one of the most serious is transverse connecting plate joint force of the hollow slab concrete hinged joints.Hinge joints as an important structure of the hollow slab bridge transverse force,its damage greatly weaken the hollow slab lateral connection,it is easy to appear the phenomenon of excessive solvating,serious impact on the lateral overall mechanical properties of the hollow slab bridge upper structure,make the safety of the hollow slab structure there is a huge hidden trouble.In view of this,many scholars analyzed the problem of the injury of hollow plate transverse hinged joint,and adopt different methods such as experimental study or numerical simulation or combination both of two,although some reinforcement method is proposed,but the essence that hinged joints as a transverse connection force structure did not change,the nature of articulated joint disease problem still can not get the solution.Thereout,this paper,by using ANSYS finite element software,first of all,for the seam tongue-and-groove hinged concrete form of the present numerical simulation,analyzes its internal actual stress condition,come up with the abuse of the connection form.To avoid the happening of disease cracking phenomenon in a hinged joint position,put forward the precast hollow slab "mortise and tenon joint" new type of lateral connection,to explore its effectiveness.First analyzing and summarizing the current computational theory of the hollow slab bridge and pointing out that for meeting the actual needs to simplify the design's irrationality,leading to the error exist that cannot be ignored.Using the software simulation of the actual vehicle load stress state in hinged joints under different conditions.After analysis we draw the conclusion,theory of design assumed that hinged joint to be shear hinge is clearly inappropriate,not only within the shear force exist in hinged joint,moreover presence of longitudinal and transverse normal stress,joints of concrete under multiaxial compressive and shearing action,increase strength weakened in hinged joint of concrete.Therefore,we put forward the new type of lateral connection "mortise and tenon joint" form,do a simple comparison between both lateral connection performance.Then using ANSYS to improve the design of a new form of the transverse joint "mortise and tenon joint",analyze the influence of the size dimension and set of the transverse prestressed steel beam for hollow slab lateral connection integrity,finally it is concluded that the reasonable size and layout form of reinforcement.Finally set up the entity model of the improved transverse connection form,after comparison and analysis between the tongue-and-groove concrete hinged joint forms and improved one,to demonstrate the effectiveness of the mortise and tenon joint forms,the conclusion summarizes the above analysis,useful suggestions for the design of precast hollow slab bridge in the future.