博物馆结构隔震前后楼层反应谱及设计谱

Floor response spectrum and design spectrum of museum structure before and after isolation

为得到博物馆隔震前后的楼层反应谱及设计谱以进行附属结构的防震设计,首先建立了非隔震、隔震两种博物馆结构有限元模型,并通过环境振动测试验证模型的准确性.然后选取了7条罕遇地震波进行时程分析,通过加速度峰值、频谱两参数进行隔震前后的楼层波及其与地震波的差异分析.进而将楼层波作为输入,通过MATLAB程序计算非隔震、隔震结构对应的楼层加速度反应谱,并根据地震抗震设计谱理论拟合用于附属结构设计的楼层设计谱.研究结果表明:有限元模型的动力特性与振动实测结果吻合较好;隔震后楼层加速度峰值较非隔震峰值降低约75%,楼层波卓越频率均与两种结构对应的自振频率相吻合,结构起主控作用;楼层反应谱是地震波与主结构共同作用的结果,反映二者的特性;最后得到了加速度标准化设计谱曲线及数学表达,隔震前、后设计谱划分区段不同,非隔震楼层设计谱有1个平台段,隔震楼层设计谱有2个平台段,设计谱研究成果可用于不同结构内部展陈等附属结构的防震设计.

To obtain the floor response spectrums and design spectrums of museum befote and after isolation and pefform seismic protection design for accessotey- structure, two finite element models of seismic non-isolated and isolated museums wete established and verified through environment vibration tests. Seven seismic motions were selected, and the difference between floor waves and seisnfic waves was analyzed through peak acceleration and frequency spectrum. Taking the floor waves as the input, the floor acceleration response spectrums before and after isolation were calculated through MATLAB. The design spectrums wete fitted according to the theory, of seismic design spectrum. The tesults show that the dynamic characteristics of finite element model（FEM） are in a good agreement with test values. The peak acceleration of isolated structme is about 75% lower than that of the non- isolated strutting. The predominant frequency of floor waves is the natural frequency of structure, which is mainly controlled by the main strutting. The floor acceleration tesponse spectrums ate the tesults of earthquake working together with strutting, which reflects the characteristics of both. The floor acceleration design response spectrums and mathematical formulas are obtained and divided into different sections before and after isolation. The non- isolated design tesponse spectrum has l flat and the isolated design tesponse spectrum has 2 flats. The tesearch results of the design spectrum can be used in the seismic protection design of the accessory- structues in different structuies.