钢板混凝土-无粘结预应力组合加固在预制箱梁加固中的应用研究

Application Research of Steel Plate Concrete-unbonded Prestressed Composite Reinforcement in Precast Box Girder Reinforcement

为了钢板混凝土组合加固技术在桥梁加固工程中更广泛的应用,对传统的组合加固技术进行优化,形成了钢板混凝土-无粘结预应力组合加固技术,提出了相应的抗弯极限承载力计算公式,同时采用ANSYS软件对加固后的预制箱梁进行了非线性有限元数值模拟对比分析,并进行了荷载试验验证了加固效果.结果表明:组合加固构造优化后整体性显著增强,通过施加无粘结预应力将钢混组合加固法由被动加固法优化为主动加固法.简化公式与有限元分析结果偏差在5%以内;加固后结构关键截面抗弯极限承载力提高25%以上,加固后结构受力明显改善.

In order to make the steel plate concrete composite reinforcement technology more widely used in bridge reinforcement engineering,the traditional composite reinforcement technology was optimized to form the steel plate concrete-unbondedprestressed composite reinforcement technology.The corresponding calculation formula of bending ultimate bearing capacity was put forward.Meanwhile,the nonlinear finite element numerical simulation and comparative analysis of the reinforced prefabricated box girder were carried out by ANSYS software,and the reinforcement effect was verified by the load test.The results show that the integrity of the composite reinforcement structure is significantly enhanced after optimization,and the steel-concrete composite reinforcement method is optimized from passive reinforcement method to active reinforcement method by applying unbondedprestress.The deviation between the simplified formula and the finite element analysis results is less than 5%.After reinforcement,the ultimate flexural capacity of key sections of the structure is increased by more than 25%,and the stress of the structure after reinforcement is obviously improved.