Vladimir K. Vostrov
Vladimir K. Vostrov

Востров Владимир Кузьмич Vladimir K. Vostrov
Doctor of Technical Sciences, Professor


Publications

On the issues of criticism and further development of the national regulatory framework for the calculation of structures for seismic impacts
Issue: #1-2024
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A scientific analysis of the provisions of the studies [1–4] devoted to the critical analysis of the state of regulatory documentation on the calculation of structures for earthquakes has been carried out. In these works, it is argued that the developers of domestic standards made a serious methodological mistake when dynamic coefficients, rather than reaction spectra, were used when setting the initial seismic information. It is believed that in foreign norms, as well as in the monographs of famous foreign scientists, the ground parts of structures during earthquakes are not affected by any external forces. This incompleteness of representations is present in the equation of horizontal vibrations in translated and domestic works and monographs, but in them, unlike the analyzed works, it is not stated that during earthquakes the ground parts of structures are not affected by any external forces. The reasons for the inadequacy of mathematical models of the interaction of foundations and structures are revealed and the equations of translational and rocking plane-parallel vibrations of a rigid structure on a pliable base are given, clearly taking into account the effect of gravity.

Development of base oscillation models and regulatory approaches to the calculation of critical structures for seismic impacts
Issue: №2 2020
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Two principal approaches to generating calculated seismic impacts, proposed in the practice of earthquake - resistant construction, were used and  refined: for the construction site and for the structure. There are special, emergency and extreme seismic loads that create an emergency situation - the occurrence of a mode of beats or resonant vibrations, as well as self-oscillations (acute resonance), leading to a violation of either the operational properties or the load-bearing capacity of the structure. Proposals are formulated for the revision of the Russian standards of earthquake-resistant construction, based on three-level impact for responsible and unique structures using the proposed refined approaches to generating calculated seismic impacts.

Design Accident Events and Emergency Seismic Loads
Issue:
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The article describing the mechanism of emergency through a sharp resonance phenomenon. Basic formulas and analytical expressions are included. It is suggested the possibility of using a sharp resonance phenomenon as the impact in the calculation of the buildings on the SSE level on seismic areas.

The maximum principle of Pontryagin and emergency seismic load
Issue:
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The work proposes the methods for determining special and emergency seismic loads and emergency calculation situations required in accordance with the current legislation. It is refined the previously proposed way of describing the structure movements with the help of nonlinear ordinary differential equations and the existence of stable limit cycles for them, leading to the appearance of stationary periodic solutions-self-oscillations. It is shown that the task of selecting a special (emergency) seismic action is reduced to the task of optimal speed, when the transition from one extreme position of the structure to another with external seismic action takes place in a minimum time. A proposal was made to apply special (emergency) harmonic seismic actions with a special frequency close to the natural oscillation frequency of the structure as a maximum design earthquake in seismic regions. Emergency seismic horizontal loads are allocated as loads that create an emergency situation. An algorithm for determining the special frequency of emergency seismic actions is presented. It is based on the comparison of the maximum displacements of structures arising from beats and self-oscillations.

Development of models of vibrations of critical structures and regulatory approaches to calculations for seismic impacts
Issue:
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The calculation of the stability of the equilibrium position required by the canceled and current norms of earthquake-resistant construction, and the calculation of the dynamic stability of various partial movements, the requirements for the necessity of which are absent both in the proposals for the norms of the new generation and in the current norms of earthquake-resistant construction, are the main ones in the calculation and design of structures taking into account their interaction with the base. Special and emergency seismic loads are identified that create an emergency situation − the occurrence of a mode of beating or resonant vibrations, as well as parametric resonance and nonlinear vibrations that occur after the loss of stability of the position of structures.