Problems of Engineering Seismology: article

Аnnotation: The article presents the results of a study of the dynamic characteristics of the response of a high-rise building under the seismic impact of a series of South Baikal earthquakes in the period 2007-2008. One of the earthquakes used in the study, the Kultuk earthquake, occurred on August 27, 2008, at 10:35 local time (UTC + 8). The epicenter of the tremors was at the bottom of Lake Baikal, 30 km from Baikalsk, 75 km south of Irkutsk. The data were obtained using an engineering seismometric station installed on a large-panel 9-story building of the 135 series. The station consists of a 16-channel 24-bit digital-to-analog converter, 5 two-component accelerometers OSP-2M installed in the basement and on the 3rd, 5th, 7th, 9th floors of the building, and two SK-1P seismic sensors in the basement and on the 9th floor. The paper compares the peak values of acceleration at the levels of the basement and the 9th floor of the building. The values of the relative amplification of the acceleration amplitudes of the 9th floor relative to the base are obtained, while it is noted that the time references of the peak accelerations do not correlate with each other. Further study of waveforms of vibration acceleration performed using wavelet analysis showed that the energy of forced vibrations of a building under seismic action is redistributed from higher frequencies to the region of low frequencies, close to the values of natural frequencies of vibrations of the building. Based on the obtained spectrograms of vibrations, the frequency-amplitude amplification factors of the building's response to seismic events were calculated for various altitude levels. The maximum gain for the 9th floor is 17 units. at the natural frequency of the building.