Safety of components, buildings and structures
Constructive-technological measures for improving the reliability of seismic protection of the assemblymonolithic frames of civil buildings in Crimea
Authors: Shalenny V. T.
Key words: seismic isolation, kinematic pipe-concrete supports, mounting accuracy, prefabricated monolithic frame
The paper considers the problem of ensuring the reliability of operation of designed buildings and structures in earthquake-prone areas, which include the Republic of Crimea. Possible ways of improving the installation technology of structures of kinematic isolation systems developed and tested by professor Kurzanov A. M. and engineer Semenov S. Yu. are shown. In cases of using traditional seismic protection, structural and technological solutions of a prefabricated monolithic frame of increased rigidity are provided, which is ensured by monolithic conjugations of its bearing elements with prefabricated fillings of walls and ceilings from light materials.
Comments of the editorial board on the article by prof. V. T. Shalenny «Constructive-technological measures for improving the reliability of seismic protection of the assembly-monolithic frames of civil buildings in Crimea»
Authors: Uzdin A. M.
Key words: seismic isolation, seismic protection, kinematic supports, installation accuracy, prefabricated monolithic frame
The great importance of the questions touched upon the paper by V. T. Shalenny «Structural and technological measures to improve the reliability of seismic protection of precast-monolithic frames of civil buildings in Crimea» and the technical solutions proposed by him for the practical implementation of seismic insulating foundations is noted. Three remarks about the paper are made. They are: the terminology «active and passive seismic isolation»; the need to assess the foundation movement during strong earthquakes; the lack the fundamental oscillation period of buildings on such foundations.
Monitoring of the state of natural and technical systems
Dangerous geological processes in Dagestan and the prospects of their study
Authors: Mamaev S. A., Yusupov A. R., Idrisov I. A., IbaevZh. G., Mamaev A. S., Suleimanov V. K.
Key words: dangerous geological processes, landslides, debris, landslides, technogenic processes
Dagestan is distinguished by a wide spread of hazardous geological processes. For some parts of the region, sharp catastrophic processes of relief reshaping are likely, the reasons for which may be different. Non-stationary processes (earthquakes, technogenic impact, climate change, heavy rainfall, etc.) play an important role among the reasons. The formation of large and super-large landslides in the region can occur independently of seismic processes. Climate warming is leading to the melting of glaciers and snow reserves in the highlands. This leads to the formation of periglacial lakes and the accumulation of water in them, which increases the likelihood of the formation of landslides, mudflows of glacial and glacial torrential genesis. For example, such a landslide can be attributed to the youngest Dyultychay landslide that descended in 2019 and the resulting lake. To reduce such hazards, it is necessary to monitor all such lakes, localize accumulations of water in their thickness and, by successively undermining the eaves and walls of these accumulations, carry out controlled release of water until critical volumes are reached. Currently, the territory of 362 settlements of Dagestan is subject to dangerous geological processes, and the total area is more than 6 thousand km2. For Dagestan, where a
high population density remains, the issues of reducing damage from hazardous geological processes, including landslides, are especially relevant. Spontaneously uncontrollably erected houses on landslide areas, for example, in Batsada, once again indicates the need for predicting organized crime groups and monitoring construction.
Composition and pre-burning properties of middle jurian argillites of mountain Dagestan
Authors: Suleymanov V. K., Yusupov A. R., Abdullaev M. Sh., Alkhulaev K. G., Mamaev A. S.
Key words: lithified rocks, mudstones, minerals, structure, chemical composition, ceramics
The urgency of the problem of development of the construction materials industry based on local raw materials and the need to search for new sources of raw materials are noted. It is emphasized that lithified rocks are of interest in this respect. The wide distribution of these rocks in Dagestan and the geology of their formation are noted. The features of the material composition of a sample of Middle Jurassic clay rocks from mountainous Dagestan are described. The results of laboratory studies of pre-firing properties of these rocks are shown. The mineral composition and structure of the rock are described. On the basis of the performed studies, it is confirmed that the mineralogical and chemical compositions of the investigated rocks and their pre-firing properties are quite favorable for the technology of obtaining ceramic building materials on their basis, and the high prospects of using them as raw materials for the production of ceramic materials are substantiated.
Composite building materials from nonmeral raw materials of the mesozoic-cenozoic sedimentary thickness
Authors: Toturbiev B. D., Mamaev S. A., Toturbiev A. B.
Key words: Mesozoic-Cenozoic sedimentary deposits, nonmetallic mineral raw materials, argillite-like clay rocks, nanodispersed sodium polysilicates, nanostructured compositions
The article provides an analysis of scientific and patent studies of nonmetallic mineral raw materials of the Mesozoic-Kaisanoic sedimentary deposits and notes that due to their poor study, they do not find much practical application in the building materials industry, although they are promising and widespread mineral raw materials. The relevance of theoretical and experimental studies aimed at the use of argillite-like clay rocks related to the Mesozoic-Cenozoic sedimentary deposits for the production of building materials for various functional purposes is noted. The results of previously carried out experimental studies of the use of argillite-like clays as mineral raw materials for the production of ceramic materials: clinker bricks, tiles, expanded clay, etc., which are mainly produced using energy-intensive firing technology, which significantly increase the cost and lengthen the technological process of manufacturing products, are presented. In this regard, it is noted that it is necessary to conduct research on argillite-like clayey rocks to obtain nanostructured composite binders using non-fired technology.
Theoretical and experimental studies. Test methods
Inspection of the technical condition of apartment buildings in the Katav-Ivanovsk city by seismic methods
Authors: Voskresenskij M. N.
Key words: inspection of buildings and structures, period (frequency) of natural vibrations, maximum velocity of displacements, engineering seismic surveys
The article is devoted to the description of the application of seismic methods for solving applied problems in engineering geophysics, in particular, the survey of buildings and structures. After an intense seismic event happened in early autumn 2018 near the Katav-Ivanovsk city, the city and district authorities decided to check the technical condition of apartment buildings. An analysis was carried out based on the results of observations and measurements of typical buildings on the example of five-story panel houses. As a result of research work, the compliance of the dynamic characteristics with the permissible values described in the regulatory documents was confirmed.
Response spectra and Fourier spectra: do we have the link between them?
Authors: Tyapin A.G.
Key words: finite duration excitation, Fourier spectra, damping in oscillators, Duhamel integral
The paper is a polemic one. It responds to numerous publications of E. N. Kurbatsky et al about response spectra and Fourier spectra. They have presented the formula linking the displacements response spectrum with zero damping in the oscillator to the absolute value of the Fourier image. In the fist part the author shows that this link is in fact not to the conventional Fourier image, but to the certain «sequestered» Fourier image, which is obtained by the time integration with the finite upper limit. For the finite duration excitation this «sequestered» Fourier image is similar to the conventional Fourier image only in case the time limit in the «sequestered» Fourier image is equal or greater than the final time point of the excitation. In other words, the link of the conventional Fourier image is established not to the spectral displacements, but to the maximal displacements achieved after the excitation is over. These displacements not always are the maximal displacement over the whole response duration. In the second part of the paper the simple example, enabling analytical calculations is considered. It confirms the conclusion that the formula under consideration is generally not correct.