外包钢板法加固刚架拱桥提升承载能力的应用与研究

Application&Research on Improving Bearing Capacity of Rigid Frame Arch Bridge Strengthened by Wrapped Steel Plate Method

为研究包裹钢板的钢混组合结构在刚架拱桥提载加固设计中的应用有效性,根据纤维模型的结果与缩尺试验梁的静载结果对比分析了钢板-混凝土的组合效果及合理计算方法。以某实际桥梁的改造加固为工程背景,比较加固结构刚度取值对结构内力、变形特性的影响;基于加固桥梁的荷载试验对理论计算方法的验证。结果表明:外包钢板法能提升桥梁的刚度和承载能力,但整体结构力学性能以钢结构的力学特性为主,内部混凝土起到防止钢板局部失稳的作用。组合结构的理论计算会过高估计结构的刚度和承载能力,而忽略组合效应,且设计方法所得承载结果与试验接近,是偏于安全的。

To study the application effectiveness of steel-concrete composite structure wrapped with steel plate in the load lifting reinforcement design of rigid frame arch bridge,the composite effect&reasonable calculation method of steel plate-concrete are analyzed according to the results of fiber model&the static load results of scale test beam.Taking the reconstruction&reinforcement of some actual bridge as the engineering background,the effects of the stiffness of the strengthened structure on the internal force&deformation characteristics of the structure are compared.Based on the load test of reinforced bridge,the theoretical calculation method is verified.The results show that the wrapped steel plate method can improve the stiffness&bearing capacity of the bridge,but the mechanical properties of the overall structure are mainly the mechanical properties of the steel structure,and the internal concrete can prevent the local instability of the steel plate.The theoretical calculation of composite structure will overestimate the stiffness&bearing capacity of the structure,while the bearing results obtained by the design method of ignoring the composite effect are close to the test,which is partial to safety.