Stress Analysis Of The Shear Hinge And Its Effect On Prestressed Concrete Truss T Frame Bridge

Prestressed concrete truss T frame bridge is a special type bridge which were started to build domestic in the 1980 s,and the project examples of this type bridges is not rich. This type bridges which is currently being operated have emerged various diseases. The frequent damage of shear hinge is one of the most serious diseases. Shear hinge as an affiliated facilities of T frame bridges has not taken enough attention. This paper studied the shear higge’s influence on the bridge and its force characteristics, at last put forward improvement program of the shear higge which could provide the reference for the daily maintenance and repair of the shear hinge of the bridge.All of these study are based on Hongtang Bridge. The main research content is as follows:1) This paper built a model of Hongtang bridge by sofeware midas/civil, calculated the shear force and displacement of shear hinge under various of loads and studed the shear higge’s force characteristics in the whole bridge strcture.For setting double independent shear hinges on the Hongtang Bridge, this paper calculated the internal force and deformation of part of Hongtang Bridge’s truss rods under the different damage form of the shear hinge, and compared with the rods when the shear hinge is in good condition to determine the degree of the influence.2) A model of the sheat hinge was built by using software ANSYS, the stress distribution of all the parts of the shear hinge under different static loads was studied. This paper has determined the relatively weak position and its peak stress which has been contrasted with the material yield strength under static stress, and it have excluded the possibility of that the shear hinge would failure caused by which it’s component reach the material ultimate strength under static stress.3) In this paper, under the condition of without considering material corrosion, the shear hinge parts in the standard of fatigue stress amplitude and fatigue life were calculated according to the the British standard, determined the fatigue easily damaged part is the bottom of the 7th screw and the area of the 5th hole of the upper plate, which is shear hinge structure parts daily maintenance shoud focus on..4) Because of the flood pond bridge design vehicle load rating for the Q- 20, relative to the current operating state is low. In this paper, the stress amplitude and fatigue life of the shear hinge structure under different overload levels has been calculated. Bolt stress amplitude is bigger and its growth significantly higher than the plate when load excess increase. The bolt’s and plate’s the fatigue life is both not less than 2 million times under the 50% overload level.5) In the case of overloading 30% of shear hinge structure puts forward improvement schemes, reduces the stress of the bolt and the plate picture, prolong its service life. Without considering the effects of corrosion and material under the bolt plate to the base 10 logarithm of life, respectively, 7.20 and 7.07. Provide a reference for shear hinge maintenance.