某百万机组钢筋混凝土侧煤仓结构抗震性能分析

Analysis of seismic performance of reinforced concrete boiler-sidebunker bay for 1 000MW unit

受工艺布置、运行检修和经济要求的限制,大型火力发电厂侧煤仓结构的质量和刚度分布不规则,对结构抗震设计不利.以抗震设防烈度7度、Ⅲ类场地的某百万机组实际工程为背景,基于有限元软件ANSYS建立结构模型,对钢筋混凝土侧煤仓间结构进行多遇地震作用下的反应谱和弹性时程分析,并进行构件抗震设计.同时采用动力弹塑性时程分析方法对其进行罕遇地震作用下的弹塑性变形验算,根据层间位移角和塑性变形等指标对其塑性阶段的抗震性能进行评估.结果表明:剪力墙的设置有效地改善了结构的刚度分布,抑制了结构的扭转效应,在罕遇地震作用下底部剪力墙和煤斗层梁柱连接处出现明显开裂和塑性变形,但结构抗震设计指标均满足相关规范限值要求,实现了“大震不倒”的设防目标.分析方法和研究结论可为同类结构的抗震设计提供参考.

By the limitation of process arrangement,maintenance and economy,the mass and stiffness distributions of boiler-side bunker bay in the large thermal power plant are irregular;that is disadvantageous to seismic design.A structure model of a real reinforced concrete boiler-side bunker bay for a 1 000MW unit is established by the ANSYS software.Both the response spectrum analysis and elastic time-history analysis are done under the frequent earthquake;seismic design for the structure is carried out.Furthermore,the elastoplastic deformation under the rare earthquake is calculated by the dynamic elastoplastic time-history analysis;according to the indexes of inter-story displacement angle and plastic deformation,the seismic performance of the structure is evaluated.The results show that the walls are helpful to improve the structure stiffness distribution and inhibit torsion effectively.Under the rare earthquake there are some cracks and plastic deformation to appear in the bottom wall and the joints of the beams supporting bunker;but the seismic design indexes meet the requirements of related specification limits;the target of“no collapse under rare earthquake”is achieved.The research method and conclusions can be used as a reference for the similar structures.