钢框架结构双层隔震体系的减震性能研究

Study on the seismic performance of the double-layer isolation system of steel frame structure

以某9层钢框架结构为研究对象,采用SAP2000有限元软件建立了6种工况分析模型,并以此进行了模态分析及罕遇地震作用下的非线性时程分析;同时,通过对比各工况下基底剪力、结构位移、层间位移、滞回曲线等指标,探讨了双层隔震体系对结构在罕遇地震作用下的减震性能,并分析了双层隔震体系中上层隔震层设置位置不同对结构减震效果的影响。结果表明:双层隔震体系结构自振周期可进一步延长;其抗震性能较普通结构的有显著提高,且其减震效果较仅基础隔震有所提升;其上部隔震层设置的高度与减震效应存在着负相关性,建议上部隔震层设置在结构的中下部;其层间剪力、楼层位移在隔震层附近存在突变,需在工程隔震设计中考虑。

Taking a 9-story steel frame structure as the object,six kinds of working condition analysis models were established by SAP2000 finite element software,and the modal analysis and nonlinear time history analysis under rare earthquake were carried out.By comparing the base shear force,structural displacement,inter-story displacement,hysteresis curve and other indicators under various working conditions,the seismic performance of the double-layer isolation system under rare earthquakes was discussed,and the influence of different positions of the upper isolation layer in the double-layer isolation system on the damping effect of the structure was analyzed.The results show that the natural vibration period of the double-layer isolation system structure can be further extended.Its seismic performance is significantly improved compared with that of ordinary structures,and the seismic reduction effect of the double-layer isolation system is improved compared with that of only base isolation.There is a negative correlation between the height of the upper isolation layer and the seismic reduction effect of the double-layer isolation system.It is suggested that the upper isolation layer should be set in the middle and lower part of the structure.The interlayer shear force and floor displacement of the double-layer isolation system have sudden changes near the isolation layer,which needs to be considered in the engineering isolation design.