Research Of Recent Earthquake Response Spectrum And Its Artificial Wave Simulation

After the 1980s, numbercial strong motion seismographs with satisfied low-frequency characteristic are largely emplaced in several nations and area. The number of strong earthquake motion record is increased and the accuracy of low-frequency stage is evidently raised. This supplies reliable basis for research into long period characteristic of earthquake motion. In recent years, people pay more attention for long period characteristic of earthquake motion which reflect by the near-fault earthquake and strong motion of medium range. Long-period seismic studies cover and improve our applicable codes of the response spectrum of long period.In this paper, a strong earthquake database is composed by 1056 bars of recent earthquake records. Then the eigenperiods are got and divided into several groups. This could determine applicable type of side, classification of design earthquake and seismic fortification intensity of each strong earthquake records. The average spectra and its fitting spectra of each group of trong earthquake records can be got by means of statistical analysis of every group of trong earthquake records. Each group of mean spectra and its fitting spectra is made compared with the corresponding response spectrum of the code. Then the difference can be found by specify the recent earthquake records of response spectrum of the code. The questions and shortage can be found in response spectrum of the code and modify or suggestions can be put forward.This paper considers the average spectrum can be got by means of the response spectrum of every group of strong earthquake records. Then the imitated spectrum could be obtained by least squares fit. Fitting with this imitated spectrum as the target spectrum, on the basis of the traditional artificial wave generation and fitting method, the corresponding group of artificial wave would be obtained. Using the fitting method in this paper, get 50 control points of real-time alteration, get 50 monitoring points of artificial waves after the 15th iteration and precision is less than five percent. The artificial waves of this paper can externalize the characteristic of recent strong earthquake. Using them in dynamic time history analysis can recover the shortage of the current response spectrum of the code.