长周期地震动弹塑性反应谱的参数影响

Parametric impact on elasto-plastic response spectra of long-period ground motion

根据长周期地震动的频谱特性,从日本强震数据网K-NET和KiK-net中,合理挑选了47条长周期地震动记录,研究长周期地震动与普通地震动的弹性反应谱的区别.结果表明:长周期地震动加速度谱的卓越周期和长周期段的谱值都明显大于普通地震动的,且其弹性位移谱的谱值比普通地震动的大很多.在此基础上,对长周期地震动弹塑性反应谱(加速度谱、位移谱、残余位移谱、强度折减系数谱)进行全面的参数影响研究,得到地震动特性(场地土质、震中距、地震动峰值加速度)和恢复力模型动力参数(屈服后刚度比、阻尼比、位移延性系数)等因素对长周期地震动弹塑性反应谱的影响规律,为长周期地震动弹塑性设计反应谱的最终建立提供有益参考.

According to the spectral characteristics of long-period ground motions, 47 long-period ground motion records were rationally selected from the strong earthquake database of Japanese K-NET and KiK-net. The differences of elastic response spectra from long-period ground to general ground motions were studied. It was found that the predominant period and spectral values of long-period elastic accelera- tion spectra with a long-period section were obviously greater than general ground motions and the val- ues of long-period elastic displacement spectra were also greater than general ground motions. Effects of ground motion characteristics （site soil texture, epicentral distance and peak ground acceleration） and dynamic parameters of the restoring model （post-yield stiffness ratio, damping ratio and displacement ductility coefficient） on long-period elastic-plastic response spectra were studied through a comprehen- sive investigation into the long-period elastic-plastic response spectra （including acceleration response spectrum, displacement response spectrum, residual displacement response spectrum and strength reduc- tion coefficient response spectrum）. The study can also provide some meaningful reference for establish- ing a long-period elastic-plastic response design spectrum.