METHOD OF SEISMIC MICROZONING Russian patent published in 1998 - IPC

FIELD: structural seismology, evaluation of intensity of vibrations with due account of properties of soils making up construction site. SUBSTANCE: seismic vibrations are excited in soil by vibration source, are recorded by geophones located on sections with different engineering-geological conditions and vibration spectrum is plotted. Maximum amplitudes and spectra and weighted mean frequencies of examined and standard soils located at distances smaller or larger than wave length of seismic vibrations are measured, nonlinear-nonelastic increments of vibration force are found from relation ΔI = 3,3lg(A_if_свi)₁(A_of_сво)₂/(A_if_свi)₂(A_of_сво)₁, where (A_i)₁ is maximum amplitude of spectrum of vibrations of tested soil located at distance smaller than length of seismic vibrations, m; (A_i)₂ is maximum amplitude of spectrum of vibrations of tested soil located at distance larger than wave length of seismic vibrations, m; (A_o)₁ is maximum amplitude of spectrum of vibrations of standard soil located at distance larger than wave length of seismic vibrations, m; (A_o)₂ is maximum amplitude of spectrum of vibrations of standard soil located at distance larger than wave length of seismic vibrations, m: (f_cbi)₁ is weighted mean frequency of spectrum of tested soil located at distance smaller than wave length of seismic vibrations, Hz; (f_cbi)₂ is weighted mean frequency of spectrum of vibrations of tested soil located at distance larger than wave length of seismic vibrations, Hz; (f_cbo)₁ is weighted mean frequency of spectrum of vibrations of standard soil located at distance smaller than wave length of seismic vibrations, Hz; (f_cbo)₂ is weighted mean frequency of spectrum of vibrations of standard soil located at distance larger than wave length of seismic vibrations, Hz. Degree of seismic effect is evaluated by values of nonlinear-nonelastic increments of vibration force. EFFECT: improved authenticity of method. 2 tbl