The article analyzes the conservation of wooden architecture on the example of wooden temples of Zaonezhie. In the 21st century, with numerous losses in wooden churches, the problem of finding an effective approach to preserving the fragile wooden heritage of Russia becomes more and more relevant.

The aim of this work is to identify approaches to preservation of wooden architecture, consider the positive and negative sides of the identified approaches in terms of preservation of the architectural heritage of the 19th, 20th, and 21st centuries.

Theoretical and practical experience of preservation of wooden architecture in these centuries is studied and summarized in relation to wooden temples of Zaonezhie. A comparative analysis of preservation approaches is carried out. The SWOT analysis provides an objective assessment of positive and negative factors of preserving the wooden church in the region, and opportunities and threats to this monument.

The paper identifies and classifies approaches to preservation of wooden monuments, the Church of Transfiguration of the Lord of Kizhi pogost and temples of Zaonezhie, in particular.

The proposed classification of approaches makes it possible to objectively assess the need for their use in preserving the wooden architecture in each specific situation. The paper considers the regional factors, which can contribute to the introduction of wooden temples in the cultural turnover. The research results can be updated on historical wooden buildings, taking into account their individual characteristics.

The article presents the analysis of the architectural complex "Balandin’s Manor" in Yeniseisk, which is little investigated and information about its construction time is very poor.

Purpose: The aim of the work is to study the formation and development of architecture of Yeniseisk, the first Russian city in Central Siberia, using previously known and newly discovered data.

Methodology/Approaches: The dendrochronological approach is used in this work.

Findings: Although the traditional typological approach does not allow to establish the time of foundation and detailed history of this complex, it is found that it refers to the end of the 18th century. The time of construction of the "Balandin’s Manor" varies between the years 1846−1864. The work carried out allowed preliminary dating of the examined cultural layers of the second floor. The approximate date determined in this work is the 18-19th centuries.

Practical implications: The research results lay a solid foundation for subsequent calendar dating of wood from archeological and architectural monuments of Yeniseisk, and can be used in lectures and reports on the history of architecture in Siberia.

The article presents the detailed analysis of well-known methodological approaches proposed by various authors to studying the emergence, growth and development of metropolis. The development genesis and complication of various theoretical approaches to the problem of metropolis uncontrolled growth are considered. Most of the existing urban theories, including those by A.E. Gutnov, are phenomenological and cannot give a convinced answer to the question: "Why is the megapolis growth unstoppable, uncontrollable and unpredictable?" This work proposes the different approach to the problem based on the canonical methodology of engineering, the city development, in particular.

The use of natural forms in architecture can be traced throughout the history of mankind. Wood is one of the first natural forms applied in construction. Wood was the basis for the first structures in ancient world. Later, people gave it spiritual significance and began to repeat a tree image using various materials (stone, concrete, wood).

The aim of this work is to analyze the origin and algorithm of updating the main building element, a column, studying the architecture of the ancient world. It is important to study the relationship between such important criteria of architectural elements and buildings as techniques and aesthetics. The findings include the evolution of column design as a logical consequence of understanding the relations between forms and structures of trees and plants, and knowledge in structure, theory, graphics, technology and computation in different time periods. During 4,000 years, the column design passed from using natural wood to post-and-lintel construction, that is widely used nowadays. After a number of changes, it is still the wood prototype, which is clearly seen in buildings in different countries and time periods. It can be assumed that further development of architecture determines the construction return to the natural form making with the richness and uniqueness of each object

The article discusses the architecture of buildings erected in Russia early in the 20th century, which are associated with the dragestil common to Western European architecture of the modern era. The general dragestil concept in cultures of different countries is given on the examples of folk and cult architecture. The article considers the activities of Holm Hansen Munthe, the founder and leader of the dragestil in Norway who developed the national program of this style. For the first time, a general overview is given for buildings that reflect the dragestil national romanticism in the Russian Empire. The article analyzes the well-known dragestil projects and buildings in the cities of Omsk, Tomsk, Vyritsa station in the Tsarskoye Selo Railway and the Circum-Baikal Railway early in the 29th century.

The paper presents a brief review of the main ideas on the extensive class of inverse problems in structural mechanics relating to the identification of design models, technical condition monitoring and finding damages. The numerical implementation of identified incorrectness of inverse problems requires regularization. References include works describing the cases of practical application of reverse problem solutions.

The paper proposes the problem solution for interaction of two following factors: perforated plate reinforcement by a stringer system and its loosening by a number of circular holes and two cracks along the x-axis near each hole. The hole and crack edges are free from external loads. The riveted plate is subjected to tension by strengthening ribs via constant stresses. The action of riveted reinforcing strengthening ribs is modeled by unknown concentrated forces applied to anchor points.

An effective solution is proposed for the reinforcement by transverse strengthening ribs of plates weakened by stress concentrators (holes, cracks) under loading. The stress intensity and ultimate loads are found depending on geometrical and physical parameters of the problem.

The previous research described estimated closeness of optimum piecewise constant section width in I-rods with stability or first eigen-frequency limits to the predicted minimum material consumption with regard to strength requirements in continuous change in variable rod parameters. It is however known that in construction, rods are generally designed with piecewise constant change in the section parameters. Besides, in another work, the criterion was formulated for assessment of optimum solutions of piecewise constant sections of I-rods with stability or the first eigen-frequency limits, without considering the strength requirements. This paper focuses on a more general problem of estimated closeness of optimum piecewise constant section width in I-rods with stability or first eigen-frequency limits to the predicted minimum material consumption with regard to strength requirements.

The paper focuses on the problem of the elasticity theory for an infinite isotropic elastic plate weakened by circular perforation. The perforated holes are filled with inclusions made of elastic material and sealed along the edges. Transverse stiffening ribs made of another elastic material are riveted to the panel symmetrically to the surface. The elastic perforated plate is subjected to uniform tensile stress (tension at infinity). The action of riveted reinforcing strengthening ribs is modeled by unknown concentrated forces applied to anchor points.

During field facilities construction in permafrost conditions, it is necessary to use modern design solutions and new software products.

High-quality and reliable engineering surveys are required to study permafrost soils and identify the main factors of geotechnical engineering conditions. One of the most important characteristics of permafrost conditions is the standard depth of seasonal soil freezing/thawing.

According to the SNiP requirements, the depth calculation of the of freezing/thawing can be determined by using thermotechnical calculations in the absence long-term observation results. This calculation is associated with the conversion of one unit of measure to another, determination of physical and thermophysical parameters of soil, correct choice of a climate station, and data recording.

The proposed software for calculating the standard depths of thawing and freezing will allow optimizing the calculations. The paper describes the algorithm and advantages of the software operation and use.

Non-destructive testing of structures is an effective way to determine their required parameters. One of the promising directions is the acoustic measurement of the pile length using two channels. This method is based on the excitation and registration of elastic waves on the pile surface. A limitation of acoustic methods is that the speed of the elastic waves in the pile is assumed to be known in advance. Research results show that the practical application of this condition can lead to a significant error. This is especially true for bored piles, where the speed of the elastic wave propagation is determined by many different factors. This paper proposes to increase the measurement accuracy of the acoustic wave speed in the bored pile. The use of two measurement channels, which implies the introduction of the specified distance between the receiving devices, made it possible to increase the measurement accuracy up to 5 %.

In aerobic conditions, many of microorganisms cause decomposition of saturated hydrocarbons. Little publications are available relative to anaerobic transformation of these compounds, which provides substantial сapiltal saving for waste water treatment. At the same time, cultures found among aerobic decomposers of petroleum products are characterized by the ability to use elements with variable valence as terminal electron acceptors in oxidation of organic substances. Their ability to decompose aliphatic hydrocarbons helps to identify some of them.

Purpose: studying the ability of a selected association of immobilized bacteria on a fibrous carrier to utilize sulfate as a terminal electron acceptor for toluene oxidation.

Methodology/approach: Analytical summarizing of results, literature review, laboratory research based on standard and modern up-to-date methodologies with the use of modern analytical equipment.

Findings: The availability of using microorganism selection is shown for expanding the range of polluting strippants in biological purification; the main directions are determined for the process intensification by immobilization of active sludge on a fibrous carrier. The ability of microorganisms to oxidize toluene under oxygen-free (anaerobic) conditions is studied in the laboratory conditions.

Research implications: monoaromatic hydrocarbons, toluene, in particular, can be changed by selected associations of decomposers using terminal electron acceptors in oxidation of nitrates and sulfates.

The paper focuses on aluminosilicate-based microspheres, whose shell represents an X-ray amorphous state, which significantly reduces their strength properties. However, a number of technological characteristics used in industry provide the formation of glass-ceramic and crystalline states of the condensed phase, which is the shell microsphere. Presently, the formation of the structure and phase composition during the interaction between aluminosilicates (the SiO2/Al2O3 ratio varies between 0−100 %) and high-temperature (≥ 5000 K) plasma is most interesting. This paper presents the research results of the structure and phase composition of the aluminosilicate-based condensed phase during the microsphere production. The X-ray phase analysis shows that after cooling, the structure and phase composition of the microsphere shells based on refractory polycrystalline materials promotes the formation of the X-ray amorphous structure at SiO2 ≥ 60 wt. % in the initial powder and the transition of γ-Al2O3 cryptocrystalline phase to high-temperature α- Al2O3 phase with the use of the initial alumina powder.

The paper presents the results of physical and chemical studies of hardening products in the cement-complex additive-water system. The choice of the modifying additive is based on the structural and chemical affinity of the additive fragments with cement, which includes highly dispersed Tarkosil Ts-38 microsilica and MT-600 peat additive. The synergistic effect of the complex additive leads to a significant improvement in the performance characteristics of hydrated cement: strength, frost resistance, water resistance, and others. Physicochemical analysis shows that the introduction of the complex additive increases the density of hydrated cement due to the formation of low-basic hydrated silicates and their kinds, such as afwillite, foshagite, and truscottite.

The article shows that the algorithm used in the road design standard and national prestandard for calculating the frost resistance of flexible pavements has errors. The analysis is carried in terms of the probability theory. Using the moments method, the problem of frost resistance of flexible pavements is solved. The general calculation allows evaluating particular options. It is proven that the algorithm proposed by the road design standard gives a result with a 0.5 probability, which cannot be acceptable. The proposed algorithm is presented in the form of equation of the frost resistance. From this equation, with an allowable value of heaving and 0.95 probability, the soil heaving is determined, which is always less than the allowable value. The known soil heaving allows to determine the thickness of the anti-frost heavy course, which is much greater than the thickness determined by algorithms proposed by the road design standard and national prestandard. Technically, the material is overspent, but the comparison is made with the error-containing algorithm. Therefore, this comparison cannot be correct. It is recommended to replace algorithms proposed by the road design standard and national prestandard with the algorithm proposed in this article.