基于拟合目标反应谱法的时程特征参数比较分析
|
摘要
利用FORTRAN语言分别编制了基于相位差谱和随机相位谱的拟合目标反应谱地震动时程合成程序。通过对合成时程特征参数的分析,探求了随机数的选取及相位谱的确定方法对合成时程的峰值及持时的影响规律。结果表明:随机数的选取及相位谱的确定方法对两种方法合成时程的峰值和持时均有影响。随机数不同对单条时程的峰值和持时的影响很大,差异甚至达1倍以上,且时程的特征参数随随机数变化的规律性不强。基于不同的相位谱确定方法得到的相位谱存在差异,据此合成的时程特征参数存在差异。在随机数和幅值谱相同的情况下,基于两种不同的方法得到的时程特征参数不同:相位谱确定方法对合成时程的最大峰值加速度(PGA)和最大峰值速度(PGV)的影响不大,基于相位差谱法得到的时程的PGV稍大于基于随机相位谱法的对应值;对有效峰值速度(EPV)的影响较大,基于随机相位谱法得到的时程的EPV值比基于相位差谱法得到的值大;对能量持时的影响很大,基于相位差谱法得到的值要远大于基于随机相位谱法得到的对应值。在结构抗震设计中,应根据结构的动力特性及关键地震作用方式来选取合适的地震动时程合成方法。
By using FORTRAN language,the fitting of the target response spectrum of ground motion method based on phase difference spectrum model and random phase spectrum was compiled.Through analysis of characteristic parameters of synthetic time,this paper probes into the influence of random number selection and determination method of phase spectrum on the peak of synthetic time and duration.It uses random phase spectrum and phase difference spectrum to set an example and calculate the time history and response spectrum of ground motion.In addition,it compares and analyzes change of the characteristic parameters —PGA,PGV,EPA,EPV,90% energy duration and 70% energy duration of synthetic time history when two methods adopt the same random number.The results of analysis show that there are differences among peak values and energy duration of synthetic time history.However,the peak value doesn't change too much.The analysis on characteristic parameters of synthetic time history of 30 selected groups of random number in above-mentioned two methods has proved this point.It shows that PGA and PGV have little difference,and EPV has some difference,but energy duration of the time history have large difference between two methods,energy duration T95-5,T80-10 based on phase difference spectrum model are higher than those of time history of random phase spectrum method,EPV is slightly lower than those of time history of random phase spectrum due to the impact of different phase spectrum.
By using FORTRAN language,the fitting of the target response spectrum of ground motion method based on phase difference spectrum model and random phase spectrum was compiled.Through analysis of characteristic parameters of synthetic time,this paper probes into the influence of random number selection and determination method of phase spectrum on the peak of synthetic time and duration.It uses random phase spectrum and phase difference spectrum to set an example and calculate the time history and response spectrum of ground motion.In addition,it compares and analyzes change of the characteristic parameters —PGA,PGV,EPA,EPV,90% energy duration and 70% energy duration of synthetic time history when two methods adopt the same random number.The results of analysis show that there are differences among peak values and energy duration of synthetic time history.However,the peak value doesn't change too much.The analysis on characteristic parameters of synthetic time history of 30 selected groups of random number in above-mentioned two methods has proved this point.It shows that PGA and PGV have little difference,and EPV has some difference,but energy duration of the time history have large difference between two methods,energy duration T95-5,T80-10 based on phase difference spectrum model are higher than those of time history of random phase spectrum method,EPV is slightly lower than those of time history of random phase spectrum due to the impact of different phase spectrum.
引文
[1]胡聿贤主编.地震安全性评价技术教程[M].北京:地震出版社,1999:324.
[2]Scanlan R H,Sachs K.Earthquake time histories and response spectra[J].Journal of the Engineering Mechanics Dirision ASCE,1974,100(EM4):635-655.
[3]Amin M,Ang A H S.Nonstationary stochastic model of earthquake motions[J].Journal of the Engineering Mechanics Division,ASCE,1968,64(EM2):559-583.
[4]霍俊荣.近场强地面运动衰减规律的研究[D].北京:国家地震局工程力学研究所,1989.
[5]Ohsaki Y.On the significance of phase content in earthquake ground motion[J].Earthquake Engineering&Structural Dynanics.1979,7(5):427-439.
[6]赵凤新.时程的相位差特性及设计地震动的合成[D].北京:国家地震局地球物理研究所,1992.
[7]俞言详.长周期地震动衰减关系研究[D].北京:国家地震局地球物理研究所,2002.
[2]Scanlan R H,Sachs K.Earthquake time histories and response spectra[J].Journal of the Engineering Mechanics Dirision ASCE,1974,100(EM4):635-655.
[3]Amin M,Ang A H S.Nonstationary stochastic model of earthquake motions[J].Journal of the Engineering Mechanics Division,ASCE,1968,64(EM2):559-583.
[4]霍俊荣.近场强地面运动衰减规律的研究[D].北京:国家地震局工程力学研究所,1989.
[5]Ohsaki Y.On the significance of phase content in earthquake ground motion[J].Earthquake Engineering&Structural Dynanics.1979,7(5):427-439.
[6]赵凤新.时程的相位差特性及设计地震动的合成[D].北京:国家地震局地球物理研究所,1992.
[7]俞言详.长周期地震动衰减关系研究[D].北京:国家地震局地球物理研究所,2002.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心