大型火电厂钢结构主厂房铰接中心支撑框架体系的振动台试验研究

为获得铰接中心支撑框架结构体系的抗震性能,以位于抗震设防烈度8度区的某大型火电厂钢结构主厂房横向最不利一榀的煤仓间部分为原型,按1∶12缩尺比例设计制作了试验模型,并对其进行了14种地震工况下的模拟地震作用振动台试验。得到了模型结构的动力特性、阻尼比及其在8度多遇、基本和罕遇烈度下的加速度和位移响应等。结果表明:8度多遇地震作用前后结构第1阶频率为4.59Hz,8度罕遇地震作用后,第1阶频率减小为4.40Hz,但梁柱仍然完好,仅有个别支撑和节点板出现了微小的平面外变形。依据试验与有限元分析结果,推算出试验原型结构在三种地震(E l Centro、CholamShandon、人工地震)的多遇烈度以及人工地震的罕遇烈度下,层间位移角均满足我国现行抗震规范要求。该体系在高烈度区也可具有良好的抗震性能。

Shaking table test of special concentrically braced steel frame with pinned connections for main structure of a large thermal power plant

In order to obtain the seismic performance of special concentrically braced frame with pinned connections(briefly denoted as SCBF-P),for a one-bay braced frame selected from a nlain plant structure of a large thermal power plant to be built in the zone with a seismic design intensity of 8 degree,a 1:12 scale two one-bay braced frame model was constructed and tested using shaking table under 14 different earthquake ground motions.The model was designed using the same structural details as the prototype structure and connected by inter-column braces and secondary beams.The dynamic properties,responses of acceleration and displacement under different earthquakes were studied.The results show that,after intensity 8 rare earthquakes,the fundamental frequency of the test model decreased to 4.40Hz from 4.59Hz,but the columns and beams still worked well,and only a few braces and gusset plates were noticed with small out-of-plane buckling.Based on the test and FEM analysis results,the maximum story drift angles of the prototype structure under intensity 8 frequent and rare earthquakes are all less than their limit values pursuant to the GB 5001 1-2001 code,validating the adequate seismic performance of the SCBF-P structural system for the use in severe seismic region.