Instrumental measure of seismic intensity based on K-Net data
Authors:   Geophysical Institute – the Affiliate of Vladikavkaz Scientific Center of the Russian Academy of Sciences, ZAALISHVILI Vladislav , MELKOV Dmitry ,   Geophysical Institute – the Affiliate of Vladikavkaz Scientific Center of the Russian Academy of Sciences, FIDAROVA Madina ,   Geophysical Institute – the Affiliate of Vladikavkaz Scientific Center of the Russian Academy of Sciences, KHAREBOV Konstantin ,   Geophysical Institute – the Affiliate of Vladikavkaz Scientific Center of the Russian Academy of Sciences
Published: July 2022

Relevance. Traditionally, seismic impacts in the practice of seismic construction are estimated by the magnitude of the peak horizontal ground acceleration. This approach, being simple and convenient for practical use, is reflected in building codes for seismic design and construction in seismically hazardous areas in most countries of the world. At the same time, studies of instrumental records show that often the value of the dynamic gain does not depend on the values of peak accelerations. In recent years, attempts have been made in the calculations of buildings and structures for seismic effects to use the values of ground vibration velocities, which, according to engineers, allow you to directly take into account the kinetic, acting and absorbed energy of the object under study. When analyzing the consequences of strong and destructive earthquakes, it is necessary to take into account the multifactorial influence of the earthquake process on buildings. In this regard, it becomes unclear what determines the seismic resistance of a structure or which impact parameter determines its seismic effect and is the most important for an adequate assessment of seismic resistance. The aim of the work is to establish the relationship between macroseismic intensity and instrumental indicators of seismic event records. Research method. The analysis was carried out according to the K-net network with a selection of records obtained in areas with different soil conditions (parameter Vs). The recording parameters, in this case, were calculated according to the methods proposed by various authors: Arias intensity, cumulative absolute velocity, Ang intensity, Hausner intensity, Fajfar measure, total energy measure, real and normalized spectrum areas, as well as weighted average frequency, predominant period and duration. The connection of each of the parameters was estimated by the method of Pearson’s correlation, Fisher’s criterion and mutual information. Research results. As a result, the parameters for a number of criteria that best describe the seismic intensity were identified. The article presents the most suitable parameters for «macroseismic intensity» instrumental measure. The highest correlation of which with the intensity, based on the use of generally accepted methodology, was: the Anga intensity (0.76), the area of the so-called. real spectrum Sr (0.73), cumulative absolute velocity CAV (0.73), Arias intensity (0.7), rms acceleration (0.68), peak horizontal displacement PHD (0.51). It should be noted that the correlation for the Hausner intensity unexpectedly amounted to only 0.38. When using machine learning (Lasso), the parameters are narrowed down. The most informative features are the peak horizontal velocity (PHV), the cumulative square of accelerations - the Arias intensity, the maximum value of the Fourier amplitude spectrum, the Anga intensity and the Fajfar measure. At the same time, the correlation for the area of the real oscillation spectrum is also quite significant.