Technical regulation and development of design standards
The analysis of the current norms of Kazakhstan. SP RK 2.03-30-2017* Construction in seismic areas
Authors: Nazarov Yu. P.
Key words: rules, seismic forces, analysis of structures for seismic effects, earthquake protection of buildings, comparison of standards of Russia and Kazakhstan
Due to the indistinct and erroneous position of the degraded Central institutions of Russia in the development of norms of earthquake-resistant construction, the initiative in this area is trying to intercept the former Soviet republics of the USSR, and now independent neighboring States.
Kazakhstan has developed such «independent» norms and announces them as the most advanced and promising. There is a need for their analysis in order to understand what is advanced and promising in them, to apply it in the development of the relevant norms of Russia, and what should not be paid attention to.
Dynamic coefficients or response spectra?
Authors: Kurbatskiy E. N. Mondrus V. L.
Key words: seismic input, dynamic coefficient, response spectrum, foreign seismic standards, Russian code
There are big differences in definition of the seismic input in the norms of the Russian Federation code and in the foreign countries standards. Almost all normative documents and guidelines for the earthquake resistance analysis of structures in technically developed countries of the world used the concept of the response spectra concept.
In the norms of the former USSR and the Russian Federation to assess the seismic effects used and continues to use the concept of «spectral coefficient of dynamism» — β. We believe that the concept is erroneous. The use of bad and erroneous terms can not only complicate the understanding of the phenomenon, but also lead to wrong decisions. Such unsuccessful terms include the terms «dynamic coefficients» used in the norms of the Russian Federation in the calculation of seismic resistance.
The displacements, velocities, or accelerations response spectra to earthquakes have a clear and understandable physical meaning. The response spectra can be represented in Codes in a standard site-independent form. Site-specific response spectra can be developed if the sites have some specific properties. For soft soil sites, characterized by soils having a low shear wave velocity or for facilities 15 km of active faults. What are the «dynamic coefficients» for seismic effects is not clear. None of the codes of the Russian Federation or in the monographs of Russian authors does not provide a definition of the «dynamic coefficient» for seismic effects, nor methods for their developing.
The concept of «dynamic coefficients» should be excluded from the normative documents, replacing them with response spectra.
Theoretical and experimental studies
Bearing strength of the suspended faзade system of cold formed steel frame (resulting from testing)
Authors: Ayrumyan E. L. Larichev A. V.
Key words: suspended facade, cold formed bent profiles, linear cassette panels, brackets, wind load, bearing strength, testing
OZLK Light Gauge Structures Plant (Odintsovo Region) has set up the production of frame elements and linear cassette panels (cold formed steel profiles) for suspended facades.
This technology is implemented for decorative surface finishing, protection of ambient climatic protection and heat insulation of outer walls (r.concrete, brick masonry and other materials, density at least 600 kg / m3) for buildings up to 40 m height.
In order to evaluate the bearing strength of this façade system, field tests of its components and segments were conducted involving operation load.
The present article is describing these methods and test results.
Design analysis, design of components, buildings and structures
Design earthquake: rationale, options and specific applications in the analysis of structures
Authors: Уздин А. М., Назарова Ш. Ш., Прокопович С. В., Акбиев Р. Т.
Key words: calculation of structures, design earthquake, maximum design earthquake, limit state, design load
The main features of the calculation of structures for the effect of the project earthquake are considered. It is noted that such calculations are carried out in Russia only for nuclear power plants. The current rules rely only on the maximum credible earthquake. The term «project earthquake» was used in the norms of 2014 by mistake and was replaced in the 2018 edition by «estimated earthquake». The design earthquake has a small repeatability from 20 to 300 years and after such earthquake the construction works in the normal mode. To carry out the corresponding calculations, it is necessary to set the level of the design load and the corresponding limit state. These issues are analyzed in the article. It is noted that in case of PZ it is necessary to ensure the efficiency of the equipment and the exclusion of panic among the population, especially for entertainment and religious buildings. This requirement should limit the acceleration and displacement levels in a certain octave range.
Безопасность земляных сооружений, оснований и фундаментов
Vibrations of soils induced by piling, in terms of the point of building
Authors: Zaalishvili V. B., Melkov D. A., Kanukov A. S., Gabaraev A. F.
Key words: pile driving, soils, seismic vibrations, spectral composition, absorption, site effect, impact on building
In the conditions of point building pile driving has a significant impact on nearby buildings, which should be taken into account when carrying out such works. The article presents for the first time the instrumental materials obtained by the Institute of structural mechanics and seismic resistance (ISMIS) of the Academy of Sciences of Georgia in the 1990s on real objects. Ground conditions were represented by soft-plastic carbonate clays, whose power varied from 4.5 to 13.0 m. the Frequency of vertical oscillations averaged f = 18-20 Hz. The horizontal oscillation frequency is lower and averages f = 13-15 Hz. In the area adjacent to the pile driving, the maximum amplitude of vertical oscillations in the near zone was 0.11-0.413 mm, in close proximity to the existing building 0.0024-0.0061 mm (at a distance of 16 m from the source). In addition to solving the direct problem of estimating the parameters (amplitude, spectral composition) of the impact on existing objects in order to ensure their safety, the paper considers the screening of seismic vibrations by trenches. Calculations of seismic effects taking into account the screen and without it are made. The features of seismic oscillations when driving piles in a pre — drilled well of smaller diameter-axisymmetric source-are considered.
Refinement of methods for dynamic loads assessment considering frame buildings in the conditions of technical seismic impact
Authors: Nuzhdin L. V., Mikhailov V. S., Konovalova S. V.
Key words: seismic response, explosion, asynchronous displacement of supports, direct dynamics
Three methods for determining the forces arising in load bearing structures in conditions of industrial seismic from explosions are considered and compared: the method of equivalent earthquakes according to spectral theory, the method of direct integration of the equations of motion in time domain with synchronous and asynchronous displacement of supports using instrumental seismograms of an explosion and equivalent impulse action. The problems are demonstrated and the applicability of the commonly used method for determining loads from explosive impacts in the form of an equivalent earthquake according to spectral theory has been questioned. The authors proposed an alternative method for solving a dynamic problem by the method of direct integration of the equations of motion in time domain.
Resource and territory development management
Features of the account of the territorial construction of online territories, the formation of which is associated with mining
Authors: Samoilov N. A.
Key words: development of territories, territorial and construction resources, town-planning, territories disturbed by industry, mining and processing of minerals
For the purposes of sustainable development, the author analyzes the experience of the formation of the national scientific urban school of revitalization of territories, the formation of which is associated with the extraction of minerals. Identified the founders, leaders and students of this direction in terms of the formation and accounting of territorial construction resources (TSR). On the example of the specific fundamental, scientific and practical works carried out by the author, the special spatial and temporal nature of the changes in the studied territories is described, on the example of coal mining. The developed schematic diagram of town-planning use of the territories violated (previously violated, violated, planned to be violated) as a result of mining activities, as well as information about its approbation in the territory of Kuzbass, the basic coal-mining area in the Russian Federation, the materials of which formed the basis of the methodology for the formation of the boundaries of the urban area of coal mining and the assessment of its territorial and construction resource at the pre-project stage of urban planning is presented.
