多层工业厂房火灾后加固设计与抗震性能分析

为探究多层钢筋混凝土工业厂房在加固前后以及火灾前后的抗震性能变化情况,围绕火灾后多层工业厂房的加固设计和抗震性能分析展开研究.首先,建立多层钢筋混凝土框架结构火灾后抗震性能的有限元分析方法;随后,介绍某多层工业厂房结构特点和火灾后结构损伤情况,据此综合利用增大截面、粘贴钢板和粘贴纤维复合材料等方法对结构进行了加固设计;进而,建立了结构三维有限元模型,开展了结构动力特性和弹性地震响应分析;最后,进行了结构的动力弹塑性分析,探究了火灾前、后结构整体的抗震性能和加固措施对火灾后结构抗震性能的改善,并探讨了不同地震动特性对多层钢筋混凝土框架抗震性能的影响.研究结果表明:火灾后,整体结构地震响应明显大于火灾前,层间位移角最大增加了143％,且不同楼层层间位移角的增大幅度与楼层受火情况密切相关;近场地震作用下的结构响应大于远场地震,罕遇地震作用下底层层间位移角在近场地震作用下可达远场地震作用的2.71倍;所提出的加固方案有效提升了结构抗震性能,罕遇地震作用下底层层间位移角平均减少115.7％.研究成果可为多层工业厂房火灾安全性评估和加固设计提供参考.

Reinforcement Design and Seismic Performance Analysis of a Multi-Story Industrial Building after a Fire

This paper focuses on the reinforcement design and seismic performance analysis of multi-story industrial building after a fire. Firstly, the finite element analysis method of seismic performance of multi-story reinforced concrete frame structure after a fire is established. Secondly, the structural characteristics and structural damage of the multi-story industrial building are introduced, based on which the reinforcement design of the structure is carried out by comprehensively using three reinforcement methods including enlarging section, pasting steel plates and pasting FRP sheets. Thirdly, a three-dimensional finite element model of the structure is established, and the dynamic characteristics and elastic seismic responses of the structure are analyzed. Finally, the dynamic elastoplastic analysis of the structure under the action of the far-field and near-field earthquakes is carried out. The seismic performances of this building before the fire are compared with those after the fire, and the performance improvement of the fired structure strengthened by the proposed measures is analyzed. Moreover, the influence of the seismic waves with different characteristics on the seismic performance of the multi-story reinforced concrete frame is discussed. The results show that after the fire, seismic responses of the structure are higher than before the fire, and the maximum drift is increased by 1.43 times, which reflects the fire position of the structure. The structural responses under the near-field earthquakes are higher than those under the far-field earthquakes, and the drift of the bottom layer under the rare near-field earthquake can reach 2.71 times that under the rare far-field earthquake. The proposed reinforcement scheme effectively improves the seismic performance of the structure, and the average drift of the bottom story under the rare earthquake is reduced by 115.7%. The research can provide a reference for fire safety assessment and reinforcement design of multi-story industrial buildings.