某连续梁桥为预应力混凝土变截面连续箱梁,采用体外预应力法进行加固处理。以施工监控实测数据为依据,采用有限单元法进行理论计算,分析张拉预应力施工中挠度和应力控制,以保证桥梁能够按照加固设计标准安全顺利完成施工并达到理想的线形。同时保证施工过程中主梁的应力在允许范围内,不因过大而偏不安全。监测结果表明,采用体外预应力技术加固后主梁跨中极限抗弯承载力能力安全储备提高,底板压应力储备提高,主梁最大拉应力降低,主梁跨中向上产生8.4mm的位移,对桥梁线形有所改善,达到了加固设计要求。 A continuous girder bridge is a prestressed concrete continuous box girder with variable cross section, which is reinforced by external prestressing method. Based on the measured data of construction monitoring, the finite element method is used to calculate the theoretical calculation of the deflection and stress in the prestressed construction of the prestressed concrete so as to ensure that the bridge can complete the construction safely and achieve the ideal linear shape according to the reinforced design standard. At the same time to ensure that the construction process of the main beam of the stress within the allowable range, not because of excessive and unsafe. The monitoring results show that the safety reserve of the mid-limit ultimate flexural capacity strengthened by external prestressing technology is increased, the compressive stress reserve of the floor is increased, the maximum tensile stress of the main girder is reduced, and the displacement of the center girder is 8.4mm, Bridge linearity has been improved to meet the design requirements of reinforcement.