针对索穹顶结构张拉难于控制和安装技术要求高的问题,提出一种只需张拉端部斜索的肋环型索穹顶结构施工成形方法.根据肋环型索穹顶结构竖压杆、脊索和斜索之间的几何关系,计算安装过程的竖压杆临时标高,设计并采用几何法安装了中国第一座索穹顸结构,验证了该施工成形方案的可行性.结果表明,几何施工法只需张拉端部斜索,索穹顶结构会自动成形,不需要大规模调整拉索的预应力,降低了施工技术要求,使索穹顶结构有可能得到普遍推广.
In consideration of the issues that the prestress process of cable dome is difficult to control and techni- cal requirements of installation is high, a geometry-based construction technique for Geiger type cable dome is proposed, in which only the outmost diagonal cables need to be pulled. The principle of geometry-based construc- tion technique is that when the distance between nodes is less than the original length of the cable, tensioning clevices are not necessary for the assembly. Based on the geometric relation of the strut, ridge cable and diagonal cable of Geiger type dome, the temporary elevations of struts during installation were calculated, and reference tables for constructions of cable domes with common geometric parameters were given. The first domestic cable dome in China was designed and assembled using geometry-based construction technique, which verified the feasibility of the construction technique. The results show that only the outmost diagonal cables need to be pulled in geometry-based construction technique, and the cable dome can automatically form the design shape. During the installation process, the prestress of the cables don't need large-scale adjustment. The geometry-based construction technique can reduce the technical requirements for construction, and could make this structure form widespread promoted.