No 12 (2025)

Thin-walled and thick-walled spherical shells are widely used in construction when creating dome structures, reservoirs and other shell structures types, many of which experience significant loads close to limit. The study considers the load-bearing capacity evaluation problem of shells with central symmetry under conditions of physical and geometric nonlinearity. Setting the study task took into account the shell elastoplastic deformation provided that the material is incompressible. The calculation method based on the generalized Hooke’s law and the deformation plasticity theory provisions using the variable elasticity parameters method. The additional loads non-negativity criterion was used for the load-bearing capacity evaluation. The described procedure allows calculating the maximum internal pressure that the shell can withstand without destruction. According to the calculation results, the maximum allowable pressure increases with the shell wall relative thickness increase. Note here that relative deformation at shell outer edge corresponding to maximum tolerable load decreases with wall thickness increase. Taking into account the physical and geometric nonlinearities of the shell allows us to evaluate the qualitative differences in the behavior of the material during plastic and elastic deformation. The circumferential stresses along the thickness of the shell wall under plastic deformation conditions are increasing. Compressive circumferential stresses can occur on the inner surface of thick-walled shells under the action of the maximum allowable pressure, which affects the picture of the stressed-deformed state.

The development and improvement of interferometry methods can currently be characterized by a transition to a higher quality level, primarily related to the use of fiber-optic technologies and an element base. The object of the study is an optoelectronic system of a fiber-optic interferometer. The subject of the study is the amplitude-frequency characteristic of the phase modulator of a fiber-optic interferometer. The results of a study of the amplitude-frequency characteristics of a Mach-Zehnder fiber-optic interferometer with a piezoelectric phase modulator are presented. The design and testing methodology of a phase modulator as part of an optoelectronic system of a Mach-Zehnder fiber interferometer have been developed.

The article considers the issue of digital footprints and their role in the construction industry. The sources of the construction entrepreneurs’ digital footprints formation are analyzed, including interaction with customers through websites and social networks, software usage, participation in online bidding and auctions. The digital footprints classification into active and passive is given and the features of their formation in the construction industry are considered. Particular attention is paid to the digital footprints for entrepreneurs: market analysis, business processes optimization and customer experience improvement. The risks associated with the digital data usage are considered, including information security issues, data misinterpretation and competitive threats. In conclusion, the prospects for the digital technologies in construction development are discussed, including artificial intelligence integration and its use for services personalization. The importance of digital footprints conscious and competent use as a key success factor in the modern construction business is emphasized.

The peculiarities of settlement development in Northeastern China (Manchuria) are revealed on the example of the largest cities in the region – Harbin, Shenyang, Dalian and Changchun. In the course of the work, historical prerequisites for the urban structure formation that affected the Manchurian territories in various periods are analyzed. The peculiarities of the settlements' development under imperial and republican China, Russia and Japan jurisdiction, as well as the Manchukuo period, are considered separately. At each stage, cities planning solutions are analyzed, buildings development patterns and features of foreign techniques integration into the Northeast China environment are revealed. The complex nature of the settlements planning structure, associated with several foreign states active influence on the regions of Manchuria is determined. It is revealed that the imperial China period was characterized by the urban structure development in accordance with classical urban planning treatises, but it manifested itself only in large settlements. The period of the Russian administration management was characterized by the complex development of administrative districts in the CER exclusion zone, in which the urban axis was a street or a two-lane building facing the railway station. Similar solutions are typical for settlements under the Japanese administration control, however, unloading diagonals systems converging in the form of three beams to the station and radial axes at the highways intersection were used here. The parallel-developing Chinese regions of the republic period are characterized by chaotic development of commercial belts between the historical Chinese core and foreign neighborhoods. The Manchukuo period was characterized by the unification of disparate structures into the unified city fabric.

In modern conditions, the problem of green construction is particularly acute. Green spaces play a special role in shaping the appearance of cities and improving the environment, level, and quality of life. This article addresses the state of green spaces in large and small cities with significant traffic and industrial activity. The article examines the impact of atmospheric air on the condition of tree species used in settlements in the Lower Amur region. The assortment of trees and shrubs for recreational and green construction should have a “good rating” primarily based on the plant’s winter hardiness. The article also discusses the main species of green plants that are widely used in urban landscaping. The key parameter in selecting the assortment was the adaptation of trees and shrubs to the climatic characteristics of the city. The influence of air quality on the condition of various tree species has been studied in detail using biological methods. Recommendations have been given for the use of certain types of green spaces, taking into account the location of green areas in relation to city highways and the intensity of traffic on them.