Study On Calculation Of Shear Bearing Capacity Of PC T-Beam Strengthened By Externally Bonded Steel Plates

The application of bonding steel plates has been widely used in the strengthening engineering because of its convenient construction,short construction period and its good engineering characteristics that can improving the stiffness of primiary components,the anti-crack performance and the diagonal shear strength.In practical engineering,due to the constraint of structure and traffic restrictions,the application of bonding steel plates strengthen pre-stressed concrete beam is used under the circumstances that the bridge unable to unload its bodyweight,PC bending members strengthened are under the secondary load condition.This paper mainly studies the calculation method of diagonal shear strength of pre-stressed concrete beam which are strengthened by the use of bonding steel plates under secondary load.Four pre-stressed concrete beams with a T-section were tested under monotonic loading in the experimental program.By the means of comparing the beams not strengthened and strengthened at secondary load condition to study the mechanical character and failure modes of the strengthened beam,and analyze the stress effect of the steel plates.Through the analysis of test results and combining finite element numerical simulation,the value of shear capacity influence parameters ?vb of bonding steel plates is related to the concrete damage degree,and the steel ration of the horizontal projiection length of oblique section,finally,the simplify formula of diagonal shear strength of pre-stressed concrete beams which are strengthened by the use of bonding steel plates were given.