钢管混凝土拉索组合拱桥索力优化研究

钢管混凝土拉索组合拱桥是一种施工中以桁受力为主,成桥后以拱受力为主的新桥型,采用柔性拉索代替传统桁式组合拱桥中混凝土斜杆,使结构成为可调体系。基于钢管混凝土拉索组合拱桥施工过程中和成桥后的受力特点,采用恒载"零弯矩"法,确定悬臂施工过程中的拉索索力;以拱肋恒载弯矩分布最优为控制目标,以拉索索力为控制变量,借助影响矩阵,确定结构的合理成桥索力。最后,通过对已建成的天子山桥的计算分析表明该方法优化效果明显。

OPTIMUM STUDY OF CABLE TENSION IN CONCRETE FILLED STEEL TUBULAR ARC-CABLE COMBINED BRIDGE

Concrete filled steel tubular arc-cable combined bridge is a new bridge type,whose structural system is adjustable. In view of its structural differences during construction range and finished state,the zero moment method and the influence matrix-based optimal method were used to find the rational pre-tension forces in soft cables. The zero moment method assumes zero moment is developed at the interface of adjoining segments under dead load. The influence matrix-based optimal method uses the longitudinal moment distribution under dead load as an objective function and the pre-tension forces in cables as optimized variables,and then determines the section moment resulting from the cable tension with the help of influence matrix. At last,taking Tian Zishan bridge as an example,the feasibility of the method is verified.