Problems of Engineering Seismology: article

Аnnotation: Comparison of the results and the estimation of application conditions of seismic microzoning numerical and instrumental methods for the sites characterized by relatively small horizontal heterogeneity of the structure and properties of the soil strata are carried out. The results of the application of the instrumental method for recording microseisms (Nakamura method) and the calculation methods of seismic stiffness and spectral transfer functions for SMZ of the territory of Oktyabrsky Island in Kaliningrad, Kaliningrad region were investigated. It is shown that the used methods of seismic microzoning gave consistent results, differing mainly in the degree of detail and completeness of information. The results of the instrumental method of recording microseisms are characterized by the greatest detail and contain the most complete real, rather than model-calculated, amplitude-frequency characteristic of the expected seismic shaking. It is concluded that for weakly seismic areas with a layered soil stratum rather similar in structure to a horizontally homogeneous model, the choice of SMZ methods should be justified by the degree of responsibility of the structures projected on the territory and, therefore, by the necessary amount of information on the amplitude-frequency characteristics of the expected vibrations and the required site distribution details in increments of seismic intensity.