大跨度钢屋盖卸载方案及现场监测

Unloading plan of larges span steel roof and its field monitoring

以西宁体育场屋盖卸载为例,在卸载过程中对其应力进行实时在线监控.监控结果表明,钢结构屋盖支撑卸载后,其主要内力杆件相对于其卸载之前的应力变化不大,且所有杆件的应力随卸载过程的进行变化都比较平缓,其监测的应力-应变在结构设计的范围之内;卸载后体育场内环各测点均较卸载前产生向下的竖向位移,而体育场外环各测点均较卸载前产生向上的竖向位移,同时短轴方向的位移大于长轴方向的位移,但是位移量都比较小;卸载完成后,测点的竖向高程均在设计范围之内.

The real-time online monitoring of stress in steel roof of Xining stadium was carried out. The monitoring result showed that： the stress variation in the rods of the steel structure was small after unloa- ding, the stress variation was smoother and gentler in the unloading process, and its monitored values of stress and strain were within the structure design range. After unloading, the points on the inner peripher- y of stadium frame moved downward with vertical displacement, while the points to on the outer periphery moved up work with vertical displacement. At the same time, the displacement of points on the end of short axis is larger than that on long axis, all the displacements being small. After unloading, the eleva- tion of measuring point were all within the design range.