预应力连续箱梁桥加固设计及验算

Design plan and checking calculation for the reinforcement of prestressed continuous box girder bridges

某预应力连续箱梁桥运营15年后,箱梁内外出现了较多的裂缝、钢筋锈蚀和台后填土沉降等病害,已影响桥梁结构的正常使用和安全。根据该桥的质量检测报告,提出了箱梁顶板采用增厚钢筋混凝土、箱室顶板内表面采用粘贴钢板和碳纤维相结合以及箱梁腹板粘贴钢板的加固方法。通过理论计算和荷载试验对加固后的桥梁承载力进行了验算和检测,结果表明,结构承载力和刚度都有明显地提高,能保证桥梁的正常使用。

A prestressed continuous box girder bridge appeared various diseases in fifteen years, for instance, cracksof the inside and outside surface of the box girder, steel corrosion and the obvious settlement of filling at backabutment. The disease has affected the normal use and safety of the bridge structure. Based on the testing reports ofthe bridge, a feasible strengthening method is put forward： The roof of box girder is strengthened by the thickreinforced concrete; The top plate of the box is strengthened by steel plate and carbon fiber, and box girder webs isstrengthened by steel plate. The carrying capacity of the reinforced bridge is checked by the theoretical calculationand the load test. The results show that the bearing capacity and stiffness of the structure are obviously improved andcan meet the requirements of normal use.