Statistical Analysis Of Normalized Acceleration Response Spectrum Based On Strong Motion Record

In aseismic design of engineering structures,the seismic response spectrum in aseismic codes can be used to express the seismic load on engineering structure;the response spectrum is determined according to the seismic zoning map and site conditions.The research on the seismic response spectrum is mainly based on two aspects,one is based on the numerical simulation method,the other is based on the statistical method of strong motion records.Now more and more scientific researchers choose the statistical methods based on strong ground motion records to study the seismic response spectrum shape and parameters for accumulation of high quality strong ground motion records in recent years.In this work,the strong motion records in NGA-West2 database and KiK-net database were selected for the analysis on normalized response spectra,including the data corresponding to Magnitude 6.0-8.0,epicenter distance 0-200km and PGA above50gal.In the statistical analysis,2055 strong motion records from four class site were used in NGA-West2 database including 437 on class ? site,1247 on class ? site,363on class ? site;and 1788 strong motion records from four class site were selected in KiK-net database including 573 on class ? site,972 on class ? site,243 on class ? site.In this work,basing on the strong motion data above,the statistical analysis of normalized acceleration response spectra were done including three main work mentioned below.(1)Basing on the present studies,the site information in two data and site classification standard,the stations site class obtained strong motion records were analyzed,and were classified to class I,II,? by China code based on V_S30 finally.(2)On the strong motion records selected from two database,the statistical analysis of normalized acceleration response spectra were done considering magnitude,epicenter distant.The results showed the correlation is more obvious between magnitude and normalized acceleration response spectra.(3)Basing on the statistical analysis results of normalized acceleration response spectra,the regression coefficient of normalized acceleration spectral value corresponding the different magnitude were gotten by linear fitting method,and the change rule of normalized acceleration spectral value vs magnitude were analyzed.Then the response spectral shape for aseismic design were analyzed on the magnitude6.0,7.0,7.5 and 8.0.At last,the comparative analysis were done between the results in this work and the response spectral shape for aseismic design in China code,and difference showed the response spectral shape in current code maybe could lead to underestimate the long period earthquake load.