Problems of quantitative estimation of seismic effects in pleistoseistic regions of strong earthquakes

A forecast of seismic effects in pleistoseistic regions is connected with e stimation of the intensity of nonlinear waves in half-space rocks in the vi cinity of earthquake focus zones. The formalized parameters of earthquake f oci - sources of elastic (seismic) waves - are Insufficient for solving pro blems of engineering seismology. This paper studies in detail the character istics of rocks in the zones of nonelastic focus deformation. Analysis of e xperimental data and theoretical generalizations permitted determination of the integral level of wave amplitudes up to fault zones, the generalized f orm of spectra, and the emission duration, as well as establishment of the correlation between the intensity of elastic-plastic waves and reduced dist ances. Also, the relative dimensions of the zones of the nonlinear deformat ion of earthquake foci have been determined. It is shown that an earthquake focus, as a source of elastic waves, may be represented as an ellipsoid. T he authors have determined the focus dimensions and performed their correla tion with a mean radius Ro - a magnitude conjugated with the length of the predominant wave of a source. It is shown that an increase in the accuracy of the forecast of seismic effects in pleistoseistic regions depends on the reliability of determining the dimensions and characteristics of nonlinear deformation. For forecasting seismic effects in the context of the energet ic criteria of strength, the coefficients of elastic-system dynamicity have been obtained.