钢筋混凝土拱桥悬臂浇注施工模型试验设计与索力优化

以西昌~攀枝花高速公路上的白沙沟1号大桥为工程背景,进行悬臂浇注施工模型试验,模拟悬臂浇注施工全过程;建立平面有限元计算模型,采用应力平衡法进行索力优化。主拱合龙前,调整计算扣索力,并对合龙后的拆索顺序进行了设计计算。结果表明,拱肋施工过程中,采用二次调索进行悬臂浇注施工,拱肋控制断面的拉应力控制在1.5 MPa以内,结构受力是安全的;成拱后控制断面基本处于均压状态,内力分布是安全合理的。为模型制作提供了技术依据和理论指导,也为原桥的设计、计算提供了参考。

Model Design and Optimization of Cable Force for Cantilevering Cast Construction of Reinforced Concrete Arch Bridge

Taking Baishagou No.1 Bridge as an example,which lies on the highway from Xichang to Panzhihua,a model test of cantilevering cast construction of arch bridge is made,which simulates roundly the course of cantilevering cast construction. A plane finite element calculation model is made for optimization of cable force by the stress-balance method.The force in the tie backs is adjusted and calculated before the closure of the arch rib at the crown.The order of removal of all tie backs is chosen after the closure of the arch rib at the crown.The results indicate that the tensile stresses of key sections are within 1.5 MPa in course of cantilevering cast construction by two-stage adjusting cable force,the structure is safety.The master sections are pressed equably and the internal force distributes rationally.It provides the technical references and theoretic guidance for the construction of model,and also,the references for the design and calculation of the original bridge.