METHOD OF SEISMIC MICROZONING Russian patent published in 2001 - IPC

FIELD: structural seismology. SUBSTANCE: proposed method deals with evaluation of seismic intensity with allowance for properties of soils composing construction site. Seismic vibrations are excited in soil with the aid of artificial source of vibration, they are recorded by geophones positioned on sections with different engineering and geological conditions, then spectra of vibrations of soils are constructed. Frequency of vibrations is determined by way of division of spectrum of horizontal vibrations by spectrum of vertical vibrations of examined and standard soils located at distance less or greater than length of wave of seismic vibrations. Increment of magnitude is found from relation , where (f2(

_H/V)i)₁ is frequency of vibrations of standard soil located at distance less than length of wave of seismic vibrations, Hz; (f_(H/V)i)₂ is frequency of vibrations of standard soil located at distance greater than length of wave of seismic vibrations, Hz; (f_(H/V)o)₁ is frequency of vibrations of examined soil located at distance less than length of wave of seismic vibrations, Hz; (f_(H/V)o)₂ is frequency of vibrations of examined soil located at distance greater than length of wave of seismic vibrations, Hz. Increments of magnitude are used to evaluate degree of seismic effect. EFFECT: enhanced reliability and accuracy of method thanks to control over contribution of inelastic phenomena to resulting soil motion. 2 tbl