Seismic impact

Seismic impact - vibrational motion of the soil caused by natural or man-made factors and causing movement or deformation of buildings and structures ^[1] . The main natural causes of seismic effects are weak and strong earthquakes, unloading of mechanical stresses of the earth's crust blocks, tidal activity, and hurricanes. Technogenic factors are understood as industrial explosions, traffic, industrial equipment, development of mineral deposits ^[1] .

Earthquake accelerogram

In Russia, the intensity of seismic impacts is measured in points (1-12) on the MSK-64 scale. Also, the peak amplitudes of the horizontal acceleration component A _{MAX of} seismic effects are confined to a 12-point scale. The addition of one point to the intensity of seismic effects means a doubling of the peak amplitude of acceleration. Fractional intensity values ​​are not used due to the nonlinearity of the macroseismic point scale.

Assessment of quantitative indicators of seismic effects is performed for a given period of their repeatability and is expressed either in points or in quantitative parameters of oscillatory movements - speed, acceleration or displacement. The results of such calculations are presented in the form of axlerograms, cycle diagrams or seismograms, as well as their spectral-amplitude parameters — peak values, frequencies, and estimates of the duration of oscillations ^[1] .