五河口预应力混凝土斜拉桥施工过程计算分析

斜拉桥安装、张拉、起拱等系统的施工全过程分析和控制技术是一项涉及斜拉桥质量和安全的关键技术问题。采用空间非线性有限元模拟了五河口斜拉桥的主梁悬臂施工过程,根据该桥实际划分的施工时段,结合有限元步进法、1阶分析法和按龄期调整的有效模量法,并考虑了几何非线性因素的影响和预应力钢筋的作用,计算了桥梁从施工到成桥任一时刻主梁和主塔受力和变形状态,编制了相应的计算程序,从理论上预测出结构在每个施工过程中的受力和变形状态。结果表明,采用该方法来确定斜拉桥的合理施工状态是可行的,结果是合理的,为该桥的施工控制提供了依据。

Construction Process Calculation Analysis for a Prestressed Concrete Cable-stayed Bridge at Wuhekou

Because of the increased span of concrete cable-stayed bridge,the construction simulation recently becomes more focused on both the design and construction.A prestressed concrete cable-stayed bridge is designed to be a double-rib box-shaped girder with 370m main span and 38.6m girder width,which will be the widest girder cable-stayed bridge in China.Using spatial nonlinear FEM,the(cantilever) construction process of a prestressed concrete cable-stayed bridge is investigated.According to the step by step finite element method,first order optimization method and the age adjusted effective modulus method,a computing program is presented.As for the prestressed concrete main beam,we consider its structural feature,predict every image of the stress and deformation of the structure during every construction stage ideally,and provide basis of control over construction.The method takes account of the effect of(geometrical) nonlinearity characteristic of longspan cable-stayed bridge as well as the additional bending moments due to the vertical(profile) of the bridge deck.