The question is what are the final goals of doing spectral analysis and what can we infer from that?
Dear khalil, We can extract the seismic kappa value in other term knowing if the soil is soft or rock. Also, doing the site effect, in other term knowing the high period of soil and ovoiding it while the parasismc design.. Best Regards
There are at least three aspects.
1. If the amplitude of the low frequency is greater than the norm, then the Pleistocene zone will be wider. See my discussion "Long mechanical waves in all physical media propagate farther than short ones. This is a general law. What is the physics of this phenomenon?".
2. If the amplitude of the high frequency is greater than the norm, then in the Pleistocene zone there will be destruction due to liquefaction of the soil. Photo by Liquefaction_at_Niigata (internet source). Such destruction is not characterized by a large number of human deaths.
3. If the coherence function of the mutual spectrum of the earthquake and the spectrum of the building's own vibration has a value greater than 0.4, then the building will be destroyed due to resonance even during an earthquake of medium magnitude. The natural frequency of the building depends on its height. The collapse of the building will also be differentiated and will depend on the height of the building. Photo 3 (internet source). Such destruction is characterized by a large number of human deaths.
Frequency spectrum of seismograms contain important information and depend on properties of the source (initiation), ray pathes (rock properties) and properties of receiver/recording equipment. If we know or can specify some of them we can deconvolve the seismogram and use spectrum to estimate the unknown parameters.
Если сейсмоприемник имеет равномерную ампдитудно частотную характеристику характеристику можно оценить степень воздействия колебаний на здания и сооружения в этом месте.
Dear Mr. Khalil Bakhtiari Asl,
If your spectrum was received by recording any earthquake at the ground level, then by doing Fourier spectrum analysis you can clearly understand which frequencies are prevailing in the ground motion of this earthquake. This is very important as having the values of the prevailing frequencies you will have a possibility to design your structure you are going to build so, that it will avoid resonance effect.
Best regards,
Mikayel Melkumyan
Doctor of Sciences (Engineering), Professor
Academician of the Saint-Petersburg Arctic Academy of Sciences Academician of the Athens Institute for Education and Research
President of the Armenian Association for Earthquake Engineering
Vice-President of the International Association of CIS Countries on Base Isolation
Member of the USA Association for Science and Technology
Foreign member of the Research Center of Seismic Resistant Structures of the Institute of Industrial Science, University of Tokyo
Eminent Expert of the Committee of Eminent Experts in International Research Base of Seismic Mitigation and Isolation of Gansu Province in China
Founder of the "Save the Yerevan Schools From Earthquakes" foundation Director of the "Melkumyan Seismic Technologies" LLC
+374 (91) 94-54-02
- Badges
- Science method