Uppc Girder Bridge Design Theory And Methods

The development of the unbonded prestressed concrete structure is reviewed at first, and then the viewpoints are put forward about some problems of the application of the unbonded prestressed technology in the bridge. In order to solve the key question of the stress of unbonded tendons under the ultimate state of carring capacity and normal service in the design of the unbonded partially prestressed concrete (UPPC)beam Birdge, this paper proposes the calculation method and formula for the stress of unbonded tendons based on the analysis of the research results and the test data.The results of the study show that the ultimate stress for unbonded tendons is relative with the ratio q, of equivalent plastic length to the depth of neutral axis in failure section,and the ? value can be taken as 9.48. This paper also considers that the stress of unbonded tendons under service load is related to the ratio 13 between the length of equivalent deformation area and the depth of neutral axis in crack section, and the 13 value can be taken as 13.52. Thus, the formula for caculating the stress of the unbonded tendons is proposed. On the basis of the formula for caculating the stress of the unbonded tendons and according to the Design Code of Highway Bridge of China,this paper proposes the caculating theory and formulas of the UPPC beam bridge strength,stress,deflection and crack width, and proposes the design method of UPPC beam bridge.