DEVELOPMENT OF A METHOD FOR IDENTIFYING SEISMIC WAVES AFFECTING BUILDINGS AND STRUCTURES

Abstract

The article proposes a modern experimental method for identifying seismic waves affecting buildings and structures during man-made explosions associated with explosives, their manufacture and use blasting methods in open-pit mine and military explosions. The method is based on analysing the time and frequency characteristics of seismogram fragments, which enables high-precision differentiation between body waves (longitudinal and transverse) and surface waves with potentially dangerous parameters for engineering structures. Such parameters become critical when the natural vibration frequencies of buildings coincide or overlap with the dominant frequencies of the waves, which may cause resonance phenomena, reduce structural bearing capacity, and lead to hazardous deformations. Clear frequency criteria for distinguishing body and surface waves have been established: body waves are characterized by frequencies above 20 Hz, while surface waves exhibit frequencies below 20 Hz. A sequential spectral analysis of time-separated fragments has been developed to refine the temporal boundaries between different wave types. Based on time-, frequency- and amplitude-based criteria, an algorithm for seismic wave identification has been developed. It includes determining the velocities of P- and S-waves, isolating time fragments of the recorded signal, and performing spectral analysis of dominant frequencies. The method was tested during blasting operations at the Demne-Dobryansky open-pit mine, allowing the determination of arrival times for different types of waves and the identification of fragments with potentially dangerous characteristics. The proposed method can be applied both to structural monitoring and technical condition assessment, as well as to evaluating environmental risks associated with the seismic impact of explosions. The developed approach also makes it possible to detect seismogram fragments with frequencies close to the natural oscillations of the protected object, record maximum vibration velocities for each type of wave, and predict the most hazardous phases of seismic action.