Метод стоячих волн в инженерной сейсмологии

A standing wave field, different from other waves by coherence property in time, is always formed in closed spaces and stratified media. Extraction of standing waves per se from recorded wave fields on filtering basis by coherence in time and conversion of nonsimultaneous observations in simultaneous standing waves records in studied objects forms the basis of standing wave method. The method performs well in study of self-induced vibrations of buildings and constructions. The maps of amplitudes and phases of standing waves in set of natural frequencies, derived with given detail and accuracy, characterize an object in full and allow to determine not only its seismic stability, but realize a diagnostics of physical state at a level of constructional elements. In seismic microzoning the standing wave method performs well as direct researchmethod of resonant properties of section. Realizing a selection of standing waves in property of coherence in time, a standing wave field is separated in upper part of section and segregated on layer resonance. As a result we have a set of section natural frequencies and maps of vibration amplification on each of frequencies. On the basis of maps of standing wave phases a resonance type is simply set. The resonances, formed as multiples between horizontal boundaries, have the same close phase on area, whereas in lenses and block mediums horizontal resonances may appear characterized by banded change of areal phase. Combination of high-accuracy study of resonant properties of areas and buildings provides a new echelon of accuracy in seismic risk assessment.