支架现浇大曲率斜拉桥初始索力确定方法

Method of Determining Initial Cable Forces for Large Curvature Cable-stayed Bridge with Full Framing Cast-in-place

为确定支架现浇大曲率斜拉桥在恒载作用下的初始索力,以主梁及索塔的弯曲、拉压和扭转应变能之和作为目标函数,考虑位移、弯矩、索力等多种约束条件,结合有限元模型确定全桥各单元内力、位移的高阶影响矩阵,并运用MATLAB中有效集法求解目标函数,从而得出了初始索力。实桥应用结果表明:该方法对支架现浇大曲率斜拉桥有良好的适用性,精度满足工程要求且应用简便,实用可靠,易于推广。

In order to determine initial cable forces of large curvature cable-stayed bridge with full framing cast-in-place under constant load,authors used the bending,torsion,tension and compression strain energy of main girder and cable-tower as objective function.Considered constraint condition,such as displacement,bending moment,cable force,finite element model was used to define internal force and to get displacement influence matrix,objective function was solved and initial cable force was got based on active set method in MATLAB.Application result of test bridge indicates that this method which can be used in large curvature cable-stayed bridge with full framing cast-in-place is simple and convenient.It is also easy to be generalized.The precision calculated by the method satisfies engineering requirements.