将施工力学与控制索原长法相结合,提出了预应力网壳结构累积滑移施工中的计算方法。施工力学以时间顺序为变量,考虑后面施工阶段对前面已成型结构的影响,体现了施工的时变性。利用索原长和张力具有唯一的对应关系,控制累积滑移索的原长来求出各施工阶段索的张拉力。最后,以预应力网壳结构模型为对象,按分阶段累积滑移的方式模拟施工过程,并研究索张拉力在滑移法施工中的变化规律。结果表明:若各施工阶段的索按计算的力进行张拉,当施工全部完成后,所有索均可以达到设计的张拉力值。
Combing the construction mechanics and the control of the initial length of cables, this paper proposed a calculation method for the accumulative sliding construction of pretensioned reticulated structures. In the method, the sequence of construction stages (in time) was taken as a variable, and the influence of subsequent construction to the prior structure was taken into account, thus, the time-dependent property of construction was considered. The cable force was calculated by controlling the initial length of cable of accumulative sliding construction according to the unique relationship between initial length and cable tension. Finally, the construction process of a prestressed reticulated shell was simulated using the multistage accumulative sliding method and the variation of cable tension during construction was investigated. It was found that all cable forces could reach the design values after construction if all cables were tensioned according to the values calculated by the proposed method in this paper.