基于结构目标位形的找形分析及预应力张拉控制方法

Form-finding Analysis of Structures Based upon the Design Configuration and Study on the Control Method of Prestress in Cables

一种常用的悬吊结构体系由巨型钢拱、固定屋盖以及连接二者之间的拉索组成,在施工过程中其变形主要由预应力索张拉和结构自重所致。由于某种使用功能的缘故,对施工完成后的结构位形,即目标位形常提出明确的要求。设定这类悬吊结构体系的设计位形就是结构的目标位形,考虑结构自重与拉索预应力的共同作用,采用正装迭代找形方法求解基于巨型钢拱与固定屋盖结构目标位形的初始安装位形,进而确定这类结构的安装预调值。文中还对预应力索的张拉顺序进行了研究,并通过比较拉索单步张拉和分阶段张拉方案的计算结果,说明了单步张拉与分阶段张拉方案的适用范围。

One commonly used suspension structural system consists of giant steel arch, fixed roof and cables prestressed between them. The deformation of the structure during construction comes mainly from the pretension of the cable and structural serf-weight. Sometimes, due to a specific reason, it＇s necessary to impose a strict restriction upon the target configuration, i.e. the structural configuration after construction was completed. Thus, the design configuration of this sort of structure was taken as the target configuration. Based on the target configuration and taking structural weight and pre-stress into consideration, a forward itemtive method was adopted to obtain the initial erection and manufacture configuration of the structure. Then, the pre-set deformation value was calculated. After that, the tension sequence of the cables was investigated theoretically. Comparison was further made between single-step and muhi-step tension schemes to reveal their scope of application.