Introduction. For many years strengthening of the compressed reinforced concrete structures was fulfilled by methods based on using reinforced concrete cages and outer metal frames. These are rather time-consuming and expensive processes. The implementation of composite materials in the construction industry made it possible to quicken and simplify the works on strengthening, however with regard to compressed elements it turned to be very resourcedemanding to increase the bearing capacity of rectangular or square section structures. This is primarily due to the limitation in compression strain of the longitudinally located carbon fiber materials and a large decreasing coefficient for transverse composite strengthening. However, the development of new methods of strengthening, including the one considered in this work, will increase the efficiency of composite materials located in the transverse direction by 5–10 times, depending on different variable factors. This article aims to develop and justify a new method of strengthening the reinforced concrete columns by using mixed concrete-composite reinforcement.
Materials and methods. This research relies on the results of theoretical calculations. The standard variant of strengthening a compressed reinforced concrete element has been considered and calculated as well as composite materials volume has been specified. Based on the standard calculation results the proposals, which take into account the effect of a new strengthening method, have been made in this article, the detailed methodology of calculation thereof has also been presented. The results of theoretical strength calculations along with comparison of the required volume of reinforcement materials are the key issues in the analysis and drawing conclusions.
Results. The research has resulted in development, calculation and justification of the new method of strengthening, which allows reducing the volume of composite materials required for strengthening the compressed reinforced concrete columns.
Discussion and conclusion. Three variants of calculating the strengthening of a reinforced concrete column with composite materials have been presented and reviewed in this work. One of which is a standard one, the other two are proposed by the authors. The developed method of strengthening implies rounding of concrete followed by jacketing with composite materials. These roundings can be considered in calculation or can be referred to as structural elements. In any case, the strengthening effect received from the proposed method becomes 5.3 and 10.5 times higher. Besides, further research ideas for continuing the development and study of the method of strengthening the centrally compressed reinforced concrete columns with composite materials are given in conclusion.

Introduction. According to the Low-Carbon Development Strategy of the Russian Federation 2050, the special attention is allocated to cities, to evaluation of the quality and comfort of population life-activity, taking into account the implementation of energy-saving measures and other technological solutions, as well as to design and construction ensuring zero carbon dioxide emissions. The quality of people’s life is characterized by the availability of social infrastructure and adjacent spaces including: educational and healthcare institutions, as well as sports, recreation and cultural facilities. Planning the optimal development of healthcare institutions network with respect to the energy efficient measures, requires the integral system of urban territory evaluation, which is the main aim of the present study.
Materials and methods. A complex task requires a multifaceted approach to systematizing the information about the state of urban territory in the following spheres: energy efficiency, green technologies, healthcare facilities network and its condition, development and character of the urban territory, environmental stability etc. In the context of low-carbon development the optimization of the healthcare network provided the use of energy-saving technologies becomes possible thanks to the use of the geographic information system.
Results. As a result of the study held with application of the systemic approach to the phased planning of the healthcare institutions network optimization and using the geographic information system as a tool for territorial and spatial analysis, there were identified the main districts that require expansion and development of social infrastructure, namely healthcare institutions, and the urban territory features — infrastructure indicators (transport) and comfort of living indicators (urban greening evaluation). The basic opportunities and ways to improve energy efficiency of healthcare buildings were determined.
Discussion and Conclusions. The long-term development of the healthcare institutions network in the city is fulfilled by means of the phased planning method implicating the differentiated normative-target approach, multi-criteria evaluation, which allows to organise sufficient medical care under conditions of the specific residing system. The implementation of the information modeling technologies, green and energy saving technologies will ensure improvement of the comfort of staying level, reduce energy consumption and ease the load on the municipal infrastructure of the city.

Introduction. The construction and operation of buildings and structures on the banks of rivers and other water reservoirs with rapidly changing water level are associated with the hazard of territories flooding and underflooding, which can lead to major material damage and even endanger the life and health of people. It’s very important to make a reliable forecast of floodable and underfloodable zones and to develop possible engineering protection measures for such territories, as well as evacuation or rescue plans for cases of emergency. In this article by the example of 2 allocated for construction potentially flooded plots in the Tuapse district of the Krasnodar region, the quantitative flooding hazard assessment is carried out based on the use of the geographic information system QGIS.
Materials and methods. In the study there were used: the analysis of existing methods for assessing underflooding and flooding of territories; the long-term observation materials of the water level in rivers and of the largest floods on the studied plots; the analysis of methods of engineering protection of territories from underflooding and flooding; the hydrogeological and hydrological processes modeling using the modern geo information system QGIS; the development of recommendations for engineering protection of the built-up lands and for design of buildings’ and structures’ bases and foundations.
Results. As a result of modeling of the underflooding and flooding processes of 2 plots of the prospective built-up lands of the Tuapse district of Krasnodar region in the geo information system QGIS, the boundaries of potential flooding zones and varying probability water rise levels have been identified. Graphical results of modeling in the QGIS system have been presented and graphs of flooding and underflooding levels have been plotted in given sections and along plot’s outline.
Discussion and Conclusions. The boundaries of the most hazardous built-up lands have been identified and the engineering protection measures have been reasoned for them. Recommendations have been developed on design and construction of buildings and structures on the plots taking into account the forecasted hazards of underflooding and flooding.

Introduction. In recent years many researchers have become interested in applying the various types of finite element method to studying of the buildings oscillation problems. In recent decades the finite element method is being successfully used for natural oscillations analysis along with the physical modeling. The scaled physical modeling and experimental approaches are also suitable for solving the complex problems. The main aim of our research is to identify the dependence of dynamic characteristics of a building frame on geometric characteristics of the frame elements. The objective of this research is to make an analysis and overview of the topic, to determine the scientific deficit, to conduct numerical and experimental studies, to formulate conclusions, to model and analyse the results. The scientific novelty consists in the possibility to use the obtained data on building frame natural oscillations depending on the geometric characteristics of the frame elements as an optimal rigidness ratio. The practical significance of the research consists in development of specific analytical relations for choosing a building frame design solution with an optimal natural frequencies parameter to be used in design and construction practice.
Materials and methods. The creation and calculation of the finite element model was carried out in the LIRA software package.
Results. As a result of calculation the frequencies and periods of building frame natural oscillations were obtained.
Discussion and conclusions. Based on the results of the building natural oscillations analysis the conclusion was made that by changing the frame elements rigidity it’s possible to select its dynamic characteristics to find the optimal design solution of structures.

Introduction. The present study is targeting the problem of choosing construction solutions for strengthening the frame of a reconstructed multi-storey administrative building. The object of the study is the former Council of Ministers building in the town of Sukhum, Republic of Abkhazia.
Materials and methods. During the examination of the building under study, instrumental and visual inspection methods were implemented, which revealed the significant deflection of the roof slab and of two supporting steel beams, as well as emergence of cracks in the load bearing structures and the destruction of partitions. According to the results of examination the dimensional-planning drawings and a structures’ defects list were elaborated. A spatial finite element model of the building was developed in the LIRA-SAPR software package, taking into account the developed dimensionalplanning solutions for the reconstruction of the facility under study. Loads and impacts were set taking into account the requirements of relevant design standards. The detected defects of the structures’ elements were considered.
Results. The dynamic calculation of the building frame by finite element method is carried out. The calculation results analysis has shown that all three forms of oscillations are torsional, which proves the structural solutions of the building frame to be complex and requires additional calculations to ensure reliability of construction solutions. The building frame dynamic loads are set taking into account the requirements for buildings with a complex structure frame. The results of the general static calculation has shown that the load-bearing structures of a building are in operating state except for the roof slab.
Discussion and Conclusions. Based on the results of a numerical experiment on modeling the operation of the roof slab, the rational solutions for its reconstruction have been developed, recommendations on considering the seismic impacts on the reconstructed building frame of the Council of Ministers have been given.