大开口索承网格结构施工过程分析与现场实测研究

Analysis and Field Test Research on Construction Process of Cable Supported Grid Structure

大开口索承网格结构是近年来提出的一种新型屋面结构形式,其预应力施工过程相当复杂。以在建的巴中体育中心项目为背景,结合实际工程探讨了大开口索承网格结构的组成要点,依据实际工程的张拉方案提出采用改进的张力补偿法得到不同张拉阶段拉索施工预应力控制值,建立了有限元分析模型,进而得到结构在不同张拉阶段的索力及节点位移。分析结果表明:拉索索力模拟值与设计值吻合较好,斜撑安装完成后,环向索最大索力及最小索力相同。同时对施工张拉过程进行现场监测,模拟值与实测值基本吻合。研究结果表明,采用改进的张力补偿法可以有效模拟不同张拉阶段拉索施工预应力控制值,对索承网格结构预应力张拉施工有较好的参考价值。

Cable-supported grid structure with large opening is a new roof structure proposed in recent years,and its pre-stressed construction process is quite complicated.Based on Bazhong sports center project under construction as the background,combined with the actual project,the key elements to the composition of the cable-supported grid structure with large opening were discussed.According to the actual project of tensioning scheme,the improved tension compensation method was proposed for the control values of prestress of cable in different stages of tensioning,and the finite element analysis model was established,and then the cable forces and displacement variation in different tension stages were obtained.The analysis results show that the simulated cable forces were in good agreement with the design values,and the maximum and minimum cable forces of the circumferential cables are the same after the installation of diagonal braces.At the same time,the field monitoring of construction tension process showed that the simulated value was basically consistent with the measured value.The results showed that the improved tension compensation method could effectively simulate the control values of pre-stress in cable construction in different tension stages,which had a good reference value for the prestressed tension construction of cable-supported grid structures.