复合式索穹顶施工误差影响及控制技术研究

以国内首个百米级复合式索穹顶结构为研究对象,分为环梁及拉索的尺寸误差控制、结构安装成型先后顺序、预应力施加方法及张拉批次、施工过程控制与模拟4个方面研究了该工程的施工技术,重点分析了环梁和拉索不同大小的误差量对索穹顶内力的影响程度,并提出相应处理措施.研究结果表明:通过将外脊索和外斜索做成可调索的方式可以消除外环梁施工误差的影响;通过调整拉索现场摆放位置可以减小下料随机误差对索穹顶内力的改变.采用分部提升整体张拉法,避免了构件产生较大位移;分级分批的预应力张拉方式,可以保证施工成型后索力值与设计值的一致性.

Research on Influence of Construction Error and Controlling Techniques of Compound Cable Dome

Taking a cable dome with new compound form whose span longer than 100 m in China as a study subject, the construction technology of this project was analyzed in 4 aspects: controlling of dimensional error of ring beam and cable; sequence of structure installation; sequence and method of tensioning; and controlling and simulation of construction process. This paper focused on analyzing the influence degree of different error level of ring beam and cables on the internal force of cable dome, and put forward the corresponding treatment measures. The research shows that adjustable cables used for outmost ridge cables and outmost diagonal cables can eliminate the construction error of ring beam, while cable random error can be reduced through optimizing field placement. Step-by-step hoisting and synchronous tensioning method can avoid large displacement of members, and prestress level is proposed to ensure the coincidence of the actual cable force and the design value.