Unbonded prestress and steel plate-concrete combined reinforcement structure for box girder or T-shaped girder

The invention discloses an unbonded prestress and steel plate-concrete combined reinforcement structure for a box girder or a T-shaped girder. The disclosed reinforcement structure comprises a bottom steel plate, steel plates in the longitudinal bridge direction and plug steel plates in the transverse bridge direction, wherein the bottom steel plate, the steel plates in the longitudinal bridge direction and the plug steel plates in the transverse bridge direction encircle a to-be-reinforced part of a bridge to form a cavity; a plurality of prestressed tendons penetrate through the cavity, concrete is poured into the cavity, and the thickness of the concrete is 10-15 cm; the stretch-draw ends of each prestressed tendon are fixed on the plug steel plates in the transverse bridge direction. The steps in the construction of the reinforcement structure are as follows: firstly, confirming the to-be-reinforced part; secondly, cleaning the surface and anchor bolts of the to-be-reinforced part; thirdly, mounting reinforcement components on the to-be-reinforced part, and encircling the to-be-reinforced part to form a cavity; pouring concrete into the cavity; finally, stretch-drawing and fixing the prestressed tendons after the concrete reaches the designed strength. The reinforcement structure provided by the invention has the characteristics of tidiness in appearance, high stability and convenience for construction.