Introduction. In 2023, an increase in cases of urban flooding was recorded worldwide. The amount of stormwater has increased manifold, but there is nowhere to apply this supernumerary resource in the cities. Water-sensitive design of territories should become a priority in the planning of cities and updating of normative documents of the urban sphere in the face of global warming.

Materials and methods. The given analysis of climatic data of the study area is of key importance in calculating the irrigation rate for the functioning of green infrastructure in urban conditions. It is proposed to consider vegetative irrigation — the most important and regulated watering activity, which is vital for all plants in urban conditions.

Results. Stormwater management will reduce irrigation costs and simplify the maintenance of urban green spaces throughout growing season. The amendments and additions proposed by the authors of the regulatory documents of the Russian Federation in the field of green infrastructure will facilitate the implementation of a new ecosystem approach in practice. The light conditions for the high-quality functioning of the green infrastructure in the study area are also considered.

Conclusions. The author’s biotopes are sustainable by technological solutions of engineering preparation of the territory, developed in the context of the spirit of the place using plants of local flora based on the developed regulatory recommendations for the new concept of water-sensitive design of the urban environment.

Introduction. The article addresses issues of methodological exchange in architectural studies and related fields of activities focused on problems of interaction between man and environment. The author makes a critical appraisal of leading modern trends in the architectural morphogenesis in foreign countries and Russia.

Materials and methods. As a result of cross comparisons made within the framework of the study of theoretical publications and full-scale materials, now the human + environment binomial is the subject of research that synthesizes almost all theoretical developments as the main code of interaction. It is clear that lines of theory and practice have not coincided in ordinary and representative architecture for a long time, and architectural theory has been transformed into a scholastic visionary science that tends towards design. This is confirmed by professional publications and materials concerning existing and designed architectural facilities considered during the preparation of the article, as well as conceptual developments made by leading architects of our time.

Results. The genetic sequence of trends in the formation of architectural stylistics typical for the most recent decades is presented in a condensed form, limited to mainstream works, while engineering characteristics of facilities are disregarded. The main creative lines and personalities of foreign “masters” of architecture are identified; present-day areas of research and the research methodology are correlated with their activities.

Conclusions. A fundamental difference is identified between social prerequisites and vectors of architectural development in Russia and worldwide. Characteristics of positive and negative manifestations of evolution of global architecture are listed. A tendency towards formation of a paradigm of “intellectual architecture”, morphological and technological choice of “pure forms”, minimalism in aesthetic programs of architecture, greater importance of principles of expediency, industrialization, standardization in design are identified; hypotheses are made in order to solve problems of human-computer polarization in the future profession of an architect.

Introduction. Being an integral part of the modern construction, concrete is a complex nonlinear material. The behaviour of concrete depends to a large extent on stress–strain state and loading history. Among the structures of newly constructed and reconstructed buildings, there are a large number of elements operating in the conditions of the triaxial stress–strain state, alternating and cyclic loading. A phenomenological material model used in the numerical methods can serve as a universal tool that allows to describe the behavior of concrete under such conditions. The aim of the research is to develop the concrete model that allows to simulate material behavior with sufficient accuracy under static short-term loading. The model should reflect the key features, which characterizes the behaviour of concrete and have an algorithm for regularizing the problem of localization of irreversible deformations.

Materials and methods. This research is based on the analytical generalization and systematization of the data received from domestic and foreign sources devoted to the plasticity theory and fracture mechanics of concrete and reinforced concrete.

Results. The model was implemented in the ANSYS finite-element software package, with the help of which it is possible to apply custom material models. Comparison of the laboratory and numerical results for concrete and reinforced concrete was made.

Conclusions. The presented model allows to simulate behavior of concrete with substantial accuracy within the static short-term loading and reflects main features of the material behavior. To regularize the problem of localization of irreversible deformations, the model uses an approach based on the crack band theory. The values of all parameters required for the utilisation of the material model are presented.

Introduction. Defects and damages of steel structures in combination with metal corrosion, stimulating the loss of local stability, can lead to their limited serviceable condition or operational unsuitability. There is no method for calculating elements with such damages. At the same time, “normative” strength testing of undamaged elements under two or more parametric loading leads to underestimated results. Therefore, the development of a reliable method for calculating the strength of elements, including undamaged ones, under general loading is relevant.

Materials and methods. A method for investigating the strength of damaged and undamaged elements of steel structures in the general case of loading, taking into account the mutual influence of forces on the actual limit state corresponding to the criterion of limited plastic deformation is proposed. The solution of the problem is carried out in dimensionless parameters in reverse order, which reduces the calculation time by several orders of magnitude.

Results. Based on the analysis of the obtained research results, an effective practical method for calculating damaged and undamaged elements is developed, which allows obtaining more reliable information about their strength. The effect of damage on strength was established, which, depending on its location relative to the acting forces N, Mx, My, can lead serviceable, limited or inoperable states. Significant strength reserves of undamaged I-beam elements were identified.

Conclusions. An analytical solution in which the weakening of the cross section is compensated by equivalent loading by fictitious forces, allowing to reduce the strength test as for an undamaged element. The discovered strength reserves of undamaged I-beam elements indicate the need to study the rods with other types of cross sections.

Introduction. The actual question of redistribution of moments in statically indeterminate reinforced concrete (RC) beams subjected to corrosion is considered. Statically indeterminate RC beams are widely used in various construction applications, and understanding how corrosion affects the redistribution of moments in such beams is important for assessing their load-bearing capacity and safety. Experimental and analytical methods are applied to study the effect of corrosion on the redistribution of moments in RC beams.

Materials and methods. To carry out this investigation, a new technique was implemented to accelerate and control the corrosion process, applied according to the experimental programme. Four two-span reinforced concrete beams, both with and without induced corrosion, were subjected to bending moments in the experimental setup. The methods involved careful application of corrosion, and the experimental programme aimed to simulate real-world conditions.

Results. The experimental results were compared for the beams with and without corrosion. The analysis revealed significant effects of corrosion on the redistribution of moments in statically indeterminate reinforced concrete beams. Furthermore, the degree of corrosion was found to be directly proportional to the increased redistribution of moments. Moreover, the proposed model can significantly determine the redistribution coefficient of moments in statically indeterminate RC beams.

Conclusions. This study highlights the significant influence of corrosion on the redistribution of moments in statically indeterminate reinforced concrete beams. The results obtained show that as the corrosion percentage increases, there is a corresponding increase in the redistribution of moments. The results obtained can provide a basis for the development of future strategies to reduce the effects of corrosion on statically indeterminate reinforced concrete beams, thereby improving structural design and construction practices.

Introduction. The reasons for the reduction of durability of flexural structures due to the violation of the protective layer of reinforcement are considered. It breaks down when cracks form. Cracks can self-heal by various methods, the most effective of which is microbial-induced precipitation of calcium carbonate.

Materials and methods. Bacillus subtilis strains VKM B-70 and VKM B-501 (All-Russian Collection of Microorganisms), microsilica, metakaolin, and fly ash were used. Bacterial activity was assessed by culturing bacterial strains from tablet specimens. The pH of the specimens was determined using the pH meter. The crack growth rate was assessed by visual inspection of the tablet specimens by the optical microscope.

Results. The results of the experiment on selection of optimal size of alginate bacterial granules for biomineral additives are shown. The effect of biomineral additives of various compositions on the overgrowth of cracks with a width of 100 to 500 µm was studied. The effect of increasing bacterial activity in the presence of the pozzolanic component is shown. The relationship between the alkalinity of the specimen medium and bacterial activity was revealed.

Conclusions. The recommended granule diameter is 1–1.8 mm. The bacterial activity in such granules increases in the presence of pozzolanic component in the composition of the additive. Fly ash was most effective in formulations with Bacillus subtilus bacteria due to its ability to lower the pH of cement-sand compositions. By lowering the pH, conditions that are more favourable are created for the vital activity of bacteria. When using complex biomineral additives, there is a significant increase in the rate of crack healing, which will allow self-healing of cracks with a width of 100 microns in just five water-air cycles.

Introduction. 3D concrete printing (3DCP), carried out with concrete and mortar mixtures based on mineral binders, including hybrid mixtures, is one of the promising methods for the concrete products industry. The analysis of the current state of research in the field of development of composite materials based on gypsum-cement-pozzolanic binder for 3DCP indicates the limitations of its use due to the short setting time of gypsum, as well as low water resistance and tensile strength of products based on it, which indicates the relevance of research, aimed at developing stable compositions of gypsum-cement-pozzolanic concrete for 3DCP, with high physical, technical and optimal rheotechnological characteristics.

Materials and methods. The production of specimens was carried out on construction 3D printer “AMT S-6044” produced by “SPETSAVIA” LLC. Standard methods for studying rheological properties, physical and technical properties of concrete were applied.

Results. The composition of gypsum-cement-pozzolanic concrete (GCPC) in 3DCP was theoretically substantiated and experimentally determined. Rational application of concrete with binder: aggregate ratio = 1:2, sand fineness modulus of Mk 3, providing the following characteristics of the control concrete composition: compressive strength — 22.1 MPa, bending strength — 4.9 MPa, average density — 1,892 kg/m3, dimensional stability 16 cm, ultimate shear stress 58.5 Pa was substantiated in 3DCP. The peculiarities of structure formation and some drawbacks of microstructure of the developed gypsum-cement-pozzolanic concrete formed by the additive manufacturing method were studied.

Conclusions. Gypsum-cement-pozzolanic concretes were developed for 3DCP with an optimal ratio of components in the binder composition. The prospects for further improvement of GCPC compositions by modifying them with multifunctional complex additives were shown.

Introduction. The impact of microorganisms on the cement stone of concrete accelerates the removal of “free calcium hydroxide” from the pore structure and promotes the decomposition of calcium-containing phases, resulting in a decrease in the strength characteristics of concrete and further destruction. Biodegradation must be taken into account when determining the durability of concrete. Mathematical modelling makes it possible to predict its condition at any stage of the life cycle of a concrete product and to establish its remaining service life.

Materials and methods. The effect of mass transfer parameters on changes in calcium hydroxide concentrations in concrete and on the intensity of its leaching into a liquid medium is shown graphically by the results of numerical modelling. The description of mass transfer processes in concrete biocorrosion was carried out using a developed mathematical model, which takes into account the influence of microorganisms and their waste products as an internal source of absorption or release of mass of “free calcium hydroxide” in concrete cement stone. The conditions for reaching the values of calcium hydroxide concentrations in cement stone corresponding to the beginning of decomposition of highly basic components are described by solving the mass transfer problem.

Results. Based on the mathematical model describing the kinetics of mass transfer, a mathematical apparatus for predicting the degree of biodegradation of cement concrete was developed. Graphical dependences are presented, which are the result of a simulated numerical experiment, describing the effect of similarity criteria (Fourier, Bio) and a coefficient taking into account phase characteristics on the dynamics and kinetics of the mass transfer process during concrete biodegradation in a wide range of system parameters. The most intense change in the kinetics and dynamics of mass transfer occurs at the initial stages of exposure to the products of microorganisms during liquid corrosion of concrete.

Conclusions. The obtained graphical dependences provide an understanding of the conditions for slowing down and intensifying mass transfer processes in the concrete – biofilm – liquid medium system. The engineering methodology of calculation of mass transfer parameters and service life of concrete is applicable at any stage of operation of reinforced concrete products and structures and makes it economically feasible to assign protective equipment and set the terms of their use.

Introduction. In view of recent trends in melting of permafrost strata, the state of cryolithozone is noted as unstable, so such exogenous geological processes as landslides are widespread.

Materials and methods. The landslide process in the Vorkuta River valley near the residential area under the conditions of seasonally frozen soils was analyzed. Based on the results of vertical electrical sounding, a geoelectric section at the landslide failure edge is presented. Statistical calculations based on geodetic data, transformation of landslide displacement time series to stationary form by detrending method, correlation analysis were carried out.

Results. Trends of time series on displacement points were determined. They had a quadratic distribution. All investigated series had strong determinacy. The components were checked for stationarity and distribution according to the normal law by estimation of mathematical expectations of the detrended series parameters. Short-term forecast of landslide process for one period was given by the criteria of standard quadratic regression model, the forecast graph is given. According to Kolmogorov–Smirnov criterion, the hypothesis of homogeneity of single series distribution for climatic parameters for the observation period was accepted. The correlation coefficients of the parameters of landslide scarp displacement and some climatic factors on the Chaddock scale ranged from inverse weak (–0.18) to significant (0.58) correlation.

Conclusions. Two possible cases of the landslide movement were presented: passive stage and the slope flattening or the beginning of a new landslide cycle. Geodetic monitoring is necessary to establish a reliable forecast. The average annual air temperature increased slightly during the observation period. A close relationship between landslide displacements and the positive average monthly air temperature values was revealed, Kcor = 0.58. A moderate connection (Kcor = 0.5) — with the average annual precipitation. Engineering recommendations for slope stabilization are proposed: installation of heat-insulating screens to the depth of seasonal soil freezing, arrangement of drainage wells in the body of the landslide and in soils up the slope.

Introduction. The growth of domestic tourism in the Russian Federation is forecasted to reach 30 % by the end of 2023 compared to the results of 2022. At the same time, ecological tourism in areas with undeveloped engineering infrastructure has become one of the trends of recent years.

Materials and methods. To solve the problems of life support of temporary accommodation facilities (glamping), a technical solution for the conversion of hydraulic wave energy in the coastal zone of Russian sea areas is proposed. The purpose of the research is a feasibility study of the application of innovative life support technology based on renewable wave energy to provide municipal resources, including fresh water, to non-permanent accommodation facilities (beach glamping). To achieve this goal, numerical research methods were used using statistical data and long-term observational data, searching for domestic and foreign sources with analysis and comparison of the contained data.

Results. Calculations of fresh water productivity are presented, taking into account the unevenness of wave characteristics (heights, periods) throughout the year using the example of the Black sea and the Sea of Japan. It is established that even taking into account the uneven wave characteristics, the Black Sea coastal zone is a commercially significant territory for implementation. The coastal zone of the Sea of Japan is a promising territory in the case of seasonal operation of facilities with the proposed technology. The payback period of the technology for operation on the Black Sea coast was determined.

Conclusions. The proposed pump-compressor is able to replace energy-consuming equipment of reverse osmosis installations — high-pressure pumps for supplying seawater to the membranes. The use of technology on the freezing seas is expedient in the non-year-round operation mode. The payback period, depending on the cost of electricity, does not exceed two years without taking into account the associated removal of useful pneumatic power.

Introduction. Modern requirements for improving the energy efficiency of life and reducing energy consumption of buildings in general dictate the development of new modern structures with high thermal protection and strength characteristics. Structures of this type include multilayer wall panels with a filler made of various highly effective thermal insulation materials. The analysis of the effectiveness of the decisions taken on the use of mineral wool fillers in a two-layer wall panel with different thickness of the outer insulation layer is carried out.

Materials and methods. The current regulatory documents regarding the provision of thermal protection of enclosing structures were used. The calculations were carried out using numerical modelling in the COMSOL Multiphysics software package, as well as by the analytical calculation method presented in the normative literature.

Results. The variants of the facade wall arrangement with different thicknesses of the external insulation layer in combination with a two-layer wall panel are considered. By conducting numerical modelling, the character of temperature distribution along the thickness of the wall panel structure under consideration is established. The analysis of the influence of inhomogeneous thermal inclusions on the equivalent heat transfer resistance of a two-layer wall panel is carried out.

Conclusions. The results of the engineering and analytical calculation of the equivalent heat transfer resistance of a two-layer wall panel, as well as numerical modelling in the COMSOL Multiphysics software package, allow to obtain an updated value of the heat transfer resistance of a two-layer wall panel, which helps to determine the minimum thickness of the outer insulation layer depending on the climatic zone of construction. The use of mineral wool fillers in the construction of double-layer wall panels increases the equivalent heat transfer resistance of the enclosing structure. An example of calculation of the equivalent heat transfer resistance of a two-layer wall panel is given, which makes it possible to determine more accurately the minimum thickness of the outer insulation layer. The proposed calculation method allows to reduce significantly the cost per unit area of the wall panel when organizing the insulation of the facade of a residential building.

Introduction. In conditions of high dynamics of changes in the external environment, the key problem of managing integrated structures of investment and construction activities is the development of effective solutions in the field of strategic development and long-term optimization. Within the framework of the study of this topical issue, it is advisable to consider the directions of strategic development of integrated structures on the basis of scenario-factor analysis.

Materials and methods. Economic modeling of the target function of the strategic development of the integrated structure of investment and construction activities, formalized in various indicators depending on strategic priorities and business model of the organization, is carried out on the basis of application of tools of factor and regression analysis based on expert assessments and a representative statistical sample over the past periods based on data on the practice of functioning of large integrated structures of investment and construction activities.

Results. Main results of the research include the systematization of alternative approaches to improving the efficiency of integrated structures of investment and construction activities used in the development and implementation of strategic management tasks for their development, the author’s classification of the factor space of strategic development of integrated structures of investment and construction activities and development scenarios of investment and construction associations based on a system of criteria and their corresponding typical situations, a formalized functional model of the target indicator of the level of strategic development of the integrated structure of investment and construction activities.

Conclusions. The results of the scenario-factor analysis and the development of the target functional model form the scientific and methodological basis and prerequisites for the development and application of approaches to modelling the strategic development of integrated structures of investment and construction activities. Further scientific research in the subject area under consideration can be carried out in a number of areas, the priority of which the author presents the development and justification of methodological approaches and tools for the formation of production programmes for strategic development based on the synchronization of investment and production potentials within the framework of business models of investment and construction activities.