SUMMARY

The novelty and complexity of this project consists in the nonlinear character of physical laws which governs the propagation processes of seismic waves. These are new aspects in the actual development of seismology, on national and international level. This is due to the character of novelty of disciplines concerning the physical properties of rocks and soils in comparison to the traditional level of theoretical seismology. Nevertheless it is necessary a high level of calculus, with a large number of geotechnical parameters, and mathematical equations specific to wave propagation. Non-linearity in seismology is a known and accepted phenomenon (Richter,1934) but for the moment not sufficient quantitative appreciations were made (Apostol, Phys. Lett. A318, 2003). An efficient tool for studying the quantitative characteristics of the nonlinear behavior of soils is the study of spectral amplification factors (SAF).
In this project we try a presentation of the quantitative aspect of the phenomena and a translation of it in mathematical language.
Through the objectives the proposed project respond meanwhile the demands for high turnout and multidisciplinary in the domain of fundamental and applicative researches, which aims the nonlinear seismology, evaluate the seismic hazard, wave propagation in complex media, pursuing scientific and social relevance.
These research directions are of great importance in seismology, because they have a considerable theoretical and applicative potential.