PC箱梁顶推施工体外预应力加固优化研究

Research on External Prestressing Reinforcement Optimization of PC Box Girder Jacking Construction

以类双层顶推施工PC箱梁为研究对象,建立该桥ANSYS有限元模型,分析了其顶推过程中钢导梁及混凝土箱梁受力规律,并根据计算结果,使用体外纵向预应力对受力薄弱部位进行加固优化,优化结果表明:体外预应力可有效降低顶推过程中应力峰值,其中钢导梁最大拉应力降幅30.8%,钢混结合段拉应力降至1.53 MPa以下,且应力集中区域面积明显减小。

The PC box girder with double-layer push-up construction is taken as the research object. The ANSYS finite element model of the bridge is established. The force law of steel guide beam and concrete box girder during the pushing process is analyzed. According to the calculation result, the external longitudinal prestressing pair is used. The weakening of the weak part is optimized. The optimization results show that the external prestress can effectively reduce the stress peak during the pushing process. The maximum tensile stress of the steel guide beam is reduced by 30.8%, and the tensile stress of the steel-mixed joint is reduced to less than 1.53 MPa. The area of the concentrated area is significantly reduced.