环形辐射状预应力张弦梁钢屋盖张拉优化

Optimization research on stretching of steel roof with orbicular radialized prestressed beam string structure

为确定结构的刚度特征及各榀张弦梁下弦拉索之间索力影响关系,采用了传统的顺序张拉法对某体育馆环形辐射状预应力张弦梁钢屋盖进行了分析.结果表明该结构较柔,导致了各拉索之间索力影响较大.根据该结论,按照对称均匀的原则选取了3种张拉方案,即一阶段张拉、两阶段张拉及三阶段张拉,运用逆向分析思路对下弦拉索进行虚拟张拉的对比仿真分析,分析过程中对拉索索力及结构位移进行了全过程的动态追踪,得出方案三为最优方案,并指出对于柔性预应力钢结构应采用逆向分析思路进行仿真分析,确定合理的张拉顺序及张拉级别有利于结构的受力与变形,并保证施工阶段结构的可靠度.

To clarify the characteristics of the structural stiffness and the relationships of stress between the bottom cables, the steel roof with orbicular radialized prestressed beam string structure is analyzed through traditional ordinal stretching method. The result indicates that the structure is relatively flexible, which leads to great influence on stress of each cable. Based on this, three stretching plans were selected according to the principle of symmetry and uniformity, i.e. one-step stretching, two-step stretching and three-step stretching. As a comparison stretching simulation analyses Of bottom cable of the beam string structure were done through converse thought. The cable stress and the structural displacement were traced dynamically in full course of simulation analysis. It comes to a conclusion that the third plan is the best of all. And it is put forward that flexible prestressed steel structure should be analyzed by converse thought. Selecting suitable stretching sequence and step would benefit the structural internal force and deformation and improve the structural reliability in construction phase.