体外预应力加固混凝土连续箱梁的体外预应力极限应力增量计算研究

已有预应力混凝土连续箱梁采用体外预应力加固设计的重要问题,包括体外束极限应力增量的计算、体外预应力次内力的分析计算以及体外预应力损失的计算.以锡澄高速公路江阴高架桥跨东横河东幅桥加固工程为研究背景,对体外束极限应力增量的计算理论展开研究.研究结果表明,在对已有预应力混凝土连续箱梁的体外预应力进行加固计算中,就体外束的极限应力计算,经过数值比较分析并与试验梁实测值对比,建议采用公路桥梁加固设计规范计算公式.

Calculating Research on Secondary Internal Forces for External Tendons Reinforcement for Concrete Continuous Box Girder

The important issues of calculations about external tendons used for reinforcing the prestressed concrete continuous box girder include the calculations of limit stress increment due to external pre-stressing, the secondary moment and the loss in the external tendons. Based on the east one of Donghenghe bridges, Jiangyin, Xicheng freeway, the problem of the limit stress increment due to external pre-stressing is studied. The results indicated that for the calculation of limit stress increment in external tendons, through the contrast with test value it suggests the formula in the Specifications for Strengthening Design of Highway Bridges. For the calculation of the limit stress increment due to external pre-stressing and through the contrast with test value, the example has proved the correctness of the specifications for strengthening design of highway bridges.