多阶循环卸载技术在屋盖施工中的应用

Application of Multi-order-cyclic Unloading Technology in Roof Construction

钢结构安装工程的卸载是一个动态过程,安装施工阶段的约束条件及荷载条件和使用阶段设计约束条件及荷载条件差异较大,需做大量的空间受力计算。必须以体系转化为原则,以变形协调为核心,实时监控为保障,建立必要的安全保障措施,才能保证钢结构安装卸载安全、可靠地进行。以某体育场为工程背景,对典型大悬挑钢管桁架钢结构施工时所采用的钢管临时支撑系统进行分区多阶循环卸载模拟,同时介绍了屋盖受力体系转换过程的施工工艺及技术措施。

Unloading of steel structure is a dynamic process, while differences with loading conditions and constraints between construction stage and using stage are large, so engineers need to do a lot of spatial force calculation. Engineers must follow the principle of system transformation, which is based on the coordinate deformation as the core, and securities are real-time monitored, then set up necessary security measures, all of these are in order to ensure the safety of steel structure installation and unloading. This paper takes a stadium project as example to simulate the temporary supporting system which is unloaded under the typical large-cantilever steel trusses by using method of multi-order-cyclic unloading during the steel structure construction. It also introduces conversion process of the construction technology and technical measures of this force system.