ANALYSIS OF THE COMBINED STRUCTURE OF THE SHAFT OF THE DNIPRO METRO BY THE FINITE ELEMENTS METHOD

Purpose. The development of construction of underground excavations of the Dnipro Metro requires analysis and scientific substantiation of design solutions based on technologies that are new for Ukraine. The aim of the scientific article is to analyze the combined design of the shaft of the Dnipro Metro by the finite element method with determination of force factors in the linings of the pile system and shotcrete system with further substantiation based on the results of design solutions to the real situation of Dnipro Metro construction. Methodology. Two finite element models were constructed for the analysis of the shaft № 1 of the Dnipro Metro by the finite element method. They reflect the combined design of the shaft, which consists of two parts. The finite-element model of the pile system, which reflects the shell of bored piles, supported by a cap beam and ring beams, is analyzed separately. The model for the shotcrete system, which is used for the second part of the shaft, which lies in a solid rock mass, is separately modeled and analyzed. Finite-element models of both systems are assigned real deformation and geometric parameters, as well as the load, which became the key to adequate calculations by the finite element method. Findings. During the numerical analysis of the combined structure of the shaft № 1 of Dnipro Metro, the force factors (normal forces and bending moments) for the pile system and the shotcrete system were determined. These results became the basis for the reinforcement of both systems. Originality. A numerical analysis of the shaft structure was performed, which provided a complete picture of the force factors that allow predicting the appearance of normal forces and bending moments in similar engineering and geological conditions. Practical value. The results of the analysis of the combined design of the shaft of the Dnipro Metro by the finite element method allowed to scientifically substantiate the design solutions and ensure high performance of both shaft systems № 1.

MODERN CONSTRUCTION TECHNOLOGIES AS A TOOLKIT OF THE TRANSITION FROM TRADITION TO MODERNISM IN CHURCH ARCHITECTURE

Purpose. Consideration and analysis of twentieth-century church architecture in which the modernist style and their modern building technology was applied, using nine churches from different countries as examples. Methodology. The use of critical analysis of scientific and methodological literature of architectural modernism of churches, virtual analysis of architectural and construction projects of modernism and their use in the construction of churches, the method of systemic, structural and activity approach. Findings. The scientific formation of the concept of architectural and church modernism has been performed. The main components of architectural and church modernism and the use of the latest architectural and construction technologies are revealed. Reasonable reasons for the slow use of Architectural Church Modernism in modern times. Examples of twentieth-century architectural church modernism are provided. Originality. An analysis of the use of twentieth-century architectural-church modernism in the world is offered. An analysis of the use of architectural and church modernism in the architectural and structural design of churches has been conducted. Practical value. The rationale for the use of architectural and church modernism in the architectural and structural design of churches has been carried out. The components of church modernism are disclosed. The result is the creation of conditions for the harmonious interaction of customers-churchmen and executors-architects in the use of modernism. There were many arguments about what the temple and temple complex should be – modern or a copy of the canonical model – it all depends on the views of the customer and the architect, their views on religion and its purpose in modern life. The dispute can be long, but creativity is unstoppable, and in the world of temple construction has always kept up with current trends in architecture and construction, using new materials, designs and technology. Understandably, there are concerns that innovations in architecture may be followed by undesirable changes in the whole church tradition, but there is no stopping the new thinking. The new generation must step forward to embrace new trends, architectural modernism of churches, also search for new trends and embody them.

PECULIARITIES OF WORK OF PROFILE PRODUCTS FROM COMPOSITE MATERIALS IN BUILDING CONSTRUCTIONS LOCATED IN SEISMIC AREAS

Purpose. The aim of the article is to reveal during the analysis the peculiarities of the work of profile products from composite materials in building structures located in seismic areas. Methodology. The structure of fiber-reinforced composite materials is given and the role of each component is explained. It is noted that recently, in the construction industry for the manufacture of basic and additional structures, composite materials are used not only on the basis of epoxy resins reinforced with glass fiber, but also on the basis of carbon, organic and other fibrous fillers. The expediency of the application of products from composite materials in the construction is highlighted. Findings. The analysis of literary sources devoted to the work of products from composite materials of simple and complex cross-section in the building structures under the influence of simple (tension, compression, torsion) and complex types of loading was conducted. Distribution of stresses acting in cross-sections of complex profile rod elements made of composite materials under bending load is shown. Features of work of profile products from composite materials in building constructions are revealed. The reasons of decrease of load-carrying ability of complex profile products made of composite materials are determined. The existing methods of increasing mechanical characteristics of products from composite materials are given. Negative consequences and disadvantages of application of existing methods of increasing mechanical characteristics of products from composite materials are formulated. Originality. On the basis of the carried out analysis conclusions about necessity of refinement of existing methods of increase of mechanical characteristics of products from composite materials are made. Practical value. During the analysis features of work of profile products from composite materials in building constructions which are the basis for development of new ways of increasing mechanical characteristics of products from composite materials in building constructions and improvement of already existing ones are revealed.

ANALYSIS OF THE COMBINATION OF METHODS OF FASTENING THE JUNCTION POINT OF A HORIZONTAL TUNNEL WITH A VERTICAL SHAFT IN CONDITIONS OF DENSE URBAN DEVELOPMENT

Purpose. The problem of compares the long-term behavior of a tunnel-well taking into account the rigid and flexible couplings in the projected structures in Ukraine with 3d digital modeling using the three-dimensional finite element method. A refined geotechnical model has also been developed, taking into account the nature of the piezometric starting conditions and the proposed piezometric conditions for assessing the long-term condition as well as a summary of the properties and dimensions of the tunnel and the shaft. Methodology. Analysis of structural connections based on the experience of building shallow subways in dense urban development on the example of construction projects in China and Mexico. Search for the optimal combination of implemented methods to achieve the optimal result. Problems of a choice of a mode with 3d digital modeling using the three-dimensional finite element method based on two assumptions; the first assumption considers the rigid connection as a monolithic concrete structure between the shaft wall and the tunnel body, and the second assumption considers a material with elastic behavior between the two structures, which in turn leads to a flexible connection. The main parameters that must be clarified and corrected by the designer of the system during commissioning are determined. Next, the soft soil model was used to perform the analyzes with end elements for compressible layers. Findings. Simulation in the application, the Plaxis software environment obtained graphs of transients for the most important operating parameters, such as the geometry of the tunnel and the indicated lining, the flotation pool, three-dimensional clusters. Originality. Scientific interest in advancing technologies used in combination. Development of an algorithm for the optimal selection of the parameters of flexibility and durability in specific conditions, to save time and simplify the calculation forms. Practical value. The analysis of the obtained results is carried out, the main focus was on the relative loads and stress concentrations in the connecting elements, namely the stresses that occur in the transverse direction of the joint. Also in articles were determined some of the advantages and disadvantages of the different connection alternatives are discussed in order to neutralize the impact of the case in the future.

JUSTIFICATION OF THE STRESS-STRAIN STATE OF THE PILE FOUNDATION USING SOFTWARE COMPLEXES

Purpose. Bridge supports with a high pile caps require more attention when calculating their strength due to the difficult operating conditions of the piles. The purpose of the scientific article is to substantiate the stress-strain state of the pile foundation of the bridge structure using software computing systems SCAD and LIRA-CAD. Methodology. An analysis of software used to automate the design of foundations was conducted. The main parameters of SCAD and LIRA-CAD software packages are yielded. With their help, finite-element models of the pile foundation of the bridge support with a high pile cap were built. The developed models maximally reflect the properties of the soil base and foundation, its pile cap and piles, geometric characteristics and the influence of the finite elements meshing is considered. Calculations were performed in SCAD and LIRA-CAD software packages with monitoring of the calculation process. Findings. During the numerical analysis of the pile foundation of the bridge structure with a high pile cap, vertical displacements, force factors (normal forces and bending moments) in the piles and stresses in the body of the support and piles were determined. Based on these results, an analysis was performed, which is combined with a comparison of the obtained results. Implementation of SCAD and LIRA-CAD software allows to significantly reduce design time, to reduce project costs, to improve the quality and efficiency of investments. Originality. A comparison of the stress-strain state obtained during the numerical analysis of SCAD and LIRA-CAD software, which proved the difference in the approach to modeling in these complexes, was conducted. Practical value. The results of substantiation of the stress-strain state of the pile foundation with the use of software complexes made it possible to verify the design solution of all elements of the foundation of the bridge structure with a high pile cap.

RESEARCH OF INNOVATIVE MECHANISMS CREATION OF MODERN BUILDING MATERIALS FOR IMPROVEMENT OF PRODUCTION PROCESSES

Purpose. To reveal the mechanism of formation of contact zones and purposeful choice of mastic composition and its substantiation on the basis of revealing of regularities of interrelations "mastic composition – waterproofing resource". Methodology. The sequence of changes in the technical condition of roofing materials, which varies from normal without damage to emergency with intermediate satisfactory and unsuitable for normal operation depending on the specific damage and leakage of the roof affects the definition of conventional material resources, means and methods of arrangement and arrangements. roofs, as well as the mechanism and kinetics of loss of serviceability are a key factor in improving the whole set of measures aimed at making technology competitive. Results. Technologies of repair of point and local damages in the form of cracks, breaks, exfoliations which are carried out by cutting and the subsequent gluing of pieces of cloths on the prepared sites with filling, allow to receive short-term results. Elimination of continuous surface damage by applying an additional layer of rolled or mastic material is associated with the inevitable preservation in the lower layers of the causes of premature loss of operational functions of the coating. The results provide an opportunity to perform non-dismantling repair and restoration work using purposefully proposed repair composition with the minimum possible cost of resources and a high degree of mechanization. The developed technology is based on the ability of the used repair composition to impregnate and saturate the adjacent surfaces with ingredients that can eliminate damage of a certain type and return the coating or protective layer of the initial waterproofing potential and strengthen it. Originality. Substantiation of possibilities of use of the residual waterproofing resource of the existing soft roof by its saturation with ingredients of the offered repair composition. Practical value. It is possible to effectively use, restore and enhance the residual waterproofing potential of bitumen-roofing roof by pneumatic spraying repair composition of the developed composition.

INFLUENCE OF STORAGE TIMES OF SLUDGE FROM THE FERROALLOY INDUSTRY ON THE PROPERTIES OF CEMENT-BASED MIXTURES

Purpose. The transition to environmentally friendly, waste-free technologies is a priority for most countries in the world. The metallurgical and construction industries make a significant contribution to the formation of large volumes of man-made waste. During the production of ferroalloys, waste is generated in the form of sludge, which is stored in sludge collectors. Sludge storage has been going on for over 25 years. In order to study the effect of the duration of storage of sludge on its properties in the compositions of dry building mixtures on a cement basis, a comparison was made of the efficiency of using sludge with different storage periods. The influence of sludge of various storage periods on the strength of dry construction is estimated. Methodology. The studies were carried out in accordance with the standard methods for determining the physical and mechanical properties of solutions from dry mixtures for the installation of self-leveling floors, specified in DSTU B V. 2.7-126: 2011 “Sludge awesome dry modified. General technical minds”. Sludge from wet gas cleaning of ferrosilicon production is stored in dumps where it is a mixture of lumps of various fractions 5…50 mm in size. To use sludge in the composition of dry building mixtures, it must be dried and crushed on a roller crusher and on a disintegrator. Findings. The best ratio of the "age" of the sludge and its percentage in the composition of the mixture was determined to increase the strength characteristics of the cement stone. Originality. The influence of the chemical nature of sludge from wet gas purifiers of ferrosilicon production on the hydration processes and strength of cement stone is analyzed. Practical value. The use of man-made waste in the formulations of dry building mixtures helps to simultaneously reduce the harmful effect on the environment of industrial enterprises and increase the mechanical and economic characteristics of cement mortars based on dry mixtures.

COMPARATIVE ANALYSIS OF NATM CONSTRUCTION TECHNOLOGIES OF DNIPRO METRO ESCALATOR TUNNEL

Purpose. On the basis of the comparative analysis to carry out a substantiation of the most expedient and rational way of strengthening of a weak massif during a construction of Dnipro metro escalator tunnels by NATM. Methodology. To achieve this goal, an analysis of construction technologies in weak soils was conducted. The most used technologies are Forepoling Umbrella System (FUS), artificial ground freezing and chemical cementation. The peculiarities of carrying out each of the technologies for the conditions of inclined production were analyzed. It is determined how each of the technologies is applied to escalator tunnels and implements the strengthening of weak soil. Findings. The advantages and disadvantages of three technologies for fixing weak soil around the escalator tunnel are identified. Based on comparative analysis, it was found that the only technology that provides increased strength parameters of loamy soils, characteristic for the upper part of the escalator tunnel of the Dnipro metro, is the technology of chemical strengthening (cementation). In some cases, if necessary, short sections of sloping course, characterized by particularly weak soil, can be supported by several pipes, without creating a continuous leading mount. The results of the analysis are the basis for further substantiation of cementation, which creates a multilayer system "reinforced soil massif – temporary fastening – permanent lining". Originality. Based on the results of comparative analysis of three technologies for escalator tunnel construction by NATM, it is proved that the use of cementation not only increases the strength of the soil during drilling, but also further in operation serves as an additional element of the multilayer system "reinforced soil massif – temporary fastening – permanent lining". Practical value. In the course of research, the substantiation of cementation as the most rational and effective technology of strengthening of the surrounding weak massif at construction of the Dnipro metro was carried out.

PROSPECTIVE TRENDS OF HARMONIOUS POSSIBILITIES IN OPTIMIZATION OF PRODUCTION SYSTEMS OF CONSTRUCTION

Purpose. Scientific formation of algorithmic support of construction organization and management processes with the use of metaheuristic methods in solving practical problems of optimal control of nonlinear dynamic production systems. Methodology. Use of metaheuristic methods of optimization, system analysis and system substantiation, use of methods of systems theory, use of methods of modeling theory for the purpose of perspective management of production systems of building branch on the basis of the general laws and principles of harmony. Results. The scientific formation of the concept of harmonious optimization of production systems of construction by the metaheuristic method of the golden section is performed. The scheme of work of the method of golden section in optimization problems of construction production is developed and the detailed visualization of this method on levels of symmetry is executed. The ways of application of the principles of harmonious management in the optimization of construction production systems in the direction of sustainable and logical development are substantiated. The components of harmonious production in improving the interaction of different departments and accelerating the response to rapid change, which will accelerate the level of success of any organization. Originality. The concept of harmonious optimization of production systems of construction by metaheuristic method of golden section is offered. The scheme of work of the method of golden ratio in optimization problems of construction production is developed and the detailed visualization of this method on levels of symmetry is executed. Practical value. The use of optimization measures to increase the efficiency of construction production is proposed to be implemented according to the developed basic algorithm for optimizing the functioning of the construction production system according to the concept of the golden ratio method. Conclusions. The substantiation of ways of application of principles of harmonious management in optimization of building production systems in the direction of steady and logical development is executed. The components of harmonious production in improving the interaction of different departments and accelerating the response to rapid change, which will accelerate the level of success of any organization. The result is the creation of all conditions for the harmonious interaction of performers and equipment at all levels of construction management, which confirms the need to develop modern approaches to production on the principles of harmony.

RESEARCH OF CONCRETE OF REINFORCED CONCRETE SLEEPERS, WHICH DECIDED DAMAGE DURING OPERATION

Purpose. On the railways of Ukraine in some areas there is an intensive premature exit sleepers due to the formation of defects that can affect the safety of trains and cause significant material losses due to a single replacement of a significant number of sleepers. The purpose of the study is to establish the causes of damage reinforced concrete sleepers on a characteristic section of the railway with their intense premature exit. Methodology. The condition of reinforced concrete sleepers of SB3 type under unlined substrate fastenings on 324-332 km of the pair track of the Odnorobivka-Bukine section of the Southern Railway was studied, where since 2007 their intensive output was observed due to defects. Findings. It is established that for 15 years of operation, as 236.3 million tons were put into operation, about 2.8 % of sleepers were replaced due to defects (44 pieces per 1 km of track). Typical defects (damages), due to which the sleepers were removed from the track, were mainly 13.2 and 13.2 according to the classification of CP-0150 – cracks and fractures of sleepers, including ones with crushing concrete. These defects were preceded by the formation of a network of thin cracks on the visible surfaces of sleepers. 3 sleepers with an initial compressive strength of 68…77 MPa produced by the Korosten Reinforced Concrete Sleeper Plant and the Gnivan Special Reinforced Concrete Plant, removed from the track due to characteristic defects, were selected and investigated. Samples were selected from the sleepers, with the help of which there was determined the final strength of concrete and microscopic examinations, including luminescence flaw detection method, were performed. It was found that the network of cracks in sleepers is spatial, mostly developed mostly beneath their top edge, the least developed above the bottom edge, and causes a decrease in compressive strength of concrete by 47…72 %. It is noted that the destruction of concrete during loading occurred behind these cracks. On the inner surfaces of the cracks there are individual grains of aggregates, which have signs of active silica content, that together with the nature of the cracks may indicate that the cause of their formation is corrosion of concrete from the interaction of cement alkali with reactive aggregates. On the surfaces of the cracks in the lower part of the sleepers leaching products were found, apparently leached by electro migration, which may indicate that corrosion processes were promoted by leakage currents on electrified DC tracks. Originality Thus, in the study area, the main cause of defects, which caused the replacement of the sleepers – was the corrosion of concrete due to the interaction of cement alkali with reactive aggregates, promoted by leakage currents, as well as a small diagram of sleepers and the use of unlined anchor intermediate rail fasteners. Practical value. The results of the study allow to establish the causes of cracks and other damage in reinforced concrete sleepers during operation and, in turn, reduce the losses of fasteners manufacturers and sleepers from defects and complaints, optimize the total cost of track repairs and subsequent track maintenance due to rational purpose of track construction, reduction of damage and replacement of sleepers during track operation.