基于“零位移法+应力平衡法”确定叠合梁斜拉桥的合理成桥索力

叠合梁斜拉桥的主梁为钢结构,桥面系为混凝土结构。针对叠合梁斜拉桥的特点,结合具体算例,采用平面双层框架模型模拟主梁。首先根据零位移法初定一个成桥索力;然后在此基础上考虑恒载和活载的共同作用,根据应力平衡法确定主梁弯矩的合理恒载可行域;最后根据索力对主梁弯矩的影响矩阵进行调整。这样所得到的索力更加符合斜拉桥的要求。

A Research of Reasonable Finished Bridge Cable Force of Superposed Beam Cable-stayed Bridge on the Basis of Zero Displacement Method&Stress Balance Method

The main beam of superposed beam cable-stayed bridge is steel structure and bridge deck system is concrete one.Aiming at the features of this type bridge,a plane double-layer framework model is adopted to simulate the main beam combined with the specific computational example.Firstly,an initial finished bridge cable force is determined by zero displacement method.Secondly,considering the combined action of dead load and live load based on the initial value,reasonable dead load feasible region of main beam bending moment is determined by stress balance method.Finally,influence matrix of main beam bending moment is adjusted according to cable force and the obtained force value can meet the demand of superposed beam cable-stayed bridge better.