Abstract: Taking Chongqing Yudong Yangtze Bridge as an example,according to the state of three-dimensional space,the installments loaded cantilever construction of prestressed long-span bridges is studied by numerical analysis method.Be-cause of the existence of pore reserved for pre-stressed,the mechanical properties of cross-section have been influenced.The comparison is carried out between it and the calculation results of plane structures.The result shows that it has obvious differences at various stages,meanwhile,it is pointed out the potential dangers these in fluences may bring to the bridges.

Key words: post-tensioning prestress, space analysis, mechanical characteristics of cross-section, numerical analysi

摘要： 以重庆鱼洞长江大桥为例,按三维空间状态,采用数值分析方法,研究了分期加载的悬臂挂篮施工的大跨径预应力桥梁,由于预留预应力孔道的存在,其横截面力学性能所受的影响,并与平面杆系结构计算结果进行了比较,结果表明,在不同阶段具有明显的差异,并据此指出这些影响可能给桥梁带来的隐患。

关键词: 后张预应力, 空间分析, 截面受力特性, 数值分析