Load-bearing Structures Of Buildings Research Articles

Assessment of the technical condition of load-bearing structures of buildings based on accident risk forecasting

Each building and structure are a complex technical system with predetermined technical parameters that must be monitored throughout the entire life cycle. The purpose of the study is to develop a methodology for quantitatively assessing the technical condition of load-bearing systems of buildings to improve their structural safety and operational suitability. The dependence of the actual wear of a building on the period of natural oscillations is determined based on the theory of predicting the risk of an accident, which allows determining an increase in the period of natural oscillations of load-bearing systems of buildings to assess the category of their technical condition. The limits of increase of the period of natural vibrations of bearing systems of buildings are defined. They allow quantitatively estimate the category of the technical condition (0-4% - normative technical condition, from 5-10% - serviceable, from 11-49% - limited serviceable, 50-95% and higher - emergency).

ОТХОДЫ СТЕКЛЯННЫХ МИКРОСФЕР КАК ПОТЕНЦИАЛЬНОЕ СЫРЬЕ ДЛЯ ПОЛУЧЕНИЯ СТРОИТЕЛЬНЫХ МАТЕРИАЛОВ

Rational use of secondary energy resources (SER) is currently given special attention. In this regard, a promising and actively developing technology of industrial waste utilization is the deposition technology. This technology consists in adding construction waste to the composition of new materials. As a result, completely new modifications of materials with improved characteristics are obtained. An acute problem is the shortage of raw lightweight components of construction mixtures on the market. Such mixtures are necessary to produce materials with high thermal insulation properties. These materials not only increase the level of comfort of living in buildings, but also due to lower density, create less load on the load-bearing structures of buildings. The use of such materials is very important for saving material and energy resources. Hollow glass microspheres are widely used as light fillers of raw material mixtures of building materials. The paper considers the physical and chemical properties of glass microsphere production wastes for the purpose of their use as micro fillers for lightweight concrete and other building materials. It is shown that these wastes have density and specific surface area comparable and even much lower than the density of traditional disperse fillers. It is established that glass microspheres production wastes can serve as an excellent raw material for lightweight concrete production. Their introduction into the composition of raw material mixtures will contribute to the reduction of costs for the extraction of natural resources and energy for their processing.

Computational Models of Dynamic Load Sources for Modeling of Construction Structures Operation Used in Monitoring of Technical Condition of Buildings and Structures

This research aims to develop principles for assessing the impact of mega-cyclic vibrodynamic loads on the reliability of construction structures. The relevance of the reasons for the development and improvement of algorithms for numerical modeling of multicycle dynamic loads on building structures is due to the steadily increasing intensity of such loads on buildings and structures in megacities, as well as the acute practical problem of significant differences in the dynamic characteristics of buildings and structures obtained as a result of mathematical modeling and determined by experimental methods. The article presents research materials on computational equivalent models of dynamic load sources for numerical modeling of the behavior of construction structures under their influence, using the method of vibroacoustic analogies. The article examines models of sources of dynamic impact on construction sites. Algorithms and final formulas for computational modeling of the simplest sources of dynamic load are developed using the method of vibroacoustic analogies. The dynamic properties of the simplest dynamic load sources were analyzed. A significant difference between the computational models of real and ideal dynamic load sources. The article presents research and development results intended for calculating the distribution of dynamic loads on elements of construction structures in industrial and civil engineering projects located in areas with high levels of transport vibrodynamic impacts. An important property of the proposed computational equivalent models of sources of dynamic impact on building structures is the possibility of computational verification of critical elements, points, or nodes of load-bearing structures of buildings and structures under dynamic overloads. The position of these critical elements, points, and nodes of load-bearing structures under dynamic loads can differ significantly from their position determined using static and quasistatic computational modeling methods.

Модель автоматизации управления процессом обследования зданий на этапе эксплуатации

The article presents a study of the possibilities of automating the inspection processes of load-bearing building structures, with a special emphasis on the use of CRM systems with specialized modules. Practical examples of the implementation of such systems in the activities of construction organizations are analyzed. The necessity of engineering and technical inspection of buildings at all stages of their life cycle is discussed, based on the relevance of information on the technical condition of structures to ensure the safety of users. A process map has been developed covering various stages, such as data preparation, task creation, accounting and reporting documentation, using Bitrix 24. The key actions involved in each stage are identified, as well as the role and interaction of various departments of the organization. The importance of using BPMN for business process modeling is emphasized, which makes it possible to improve the management and coordination of work, reduce the risks of errors and increase the deadline for completing tasks. The work offers a systematic approach to conducting building surveys, covering key aspects of automation and process organization, which can significantly improve the quality and efficiency of surveys in the construction industry. Such modeling makes it possible to optimize the interaction between specialists, minimize the likelihood of errors and speed up the execution of work, ensuring systematization and control at all stages of the examination.

Restoration of Load-Bearing Structures of Buildings after Accidents

Restoration of Load-Bearing Structures of Buildings after Accidents

DEVELOPMENT OF MODELS COMPLEX OSCILLATIONS FOR AUTOMATION SYSTEMS OF VIBROACOUSTIC OPERATIONAL SAFETY CONTROL OF BUILDINGS AND STRUCTURES

Problem statement. Long-term safe operation of buildings and structures is impossible without determining the stability of their load-bearing elements, especially after shocks and dynamic loads under the influence of explosions and fires. In such conditions, reliable and productive monitoring of the reliability of buildings and structures is a critical element in increasing human safety. Vibroacoustic is an effective and informative method that allows for non-destructive assessment of the condition of concrete, reinforced concrete, brick, multi-layer walls and other types of structures. However, to increase the speed and quality of determining the state of objects, maximum automation of the vibroacoustic method is required. Purpose of the study. Increasing the productivity and reliability of vibroacoustic monitoring of buildings and structures by automating the impact action with specified parameters based on the development of dynamic models of complex oscillations. Methods. Analytical studies of dynamic and kinematic models of the exciter of mechanical vibrations, computer modeling, laboratory tests of the vibration generator control system. Research results. Models of complex oscillations have been developed to improve reliability and implement new control laws that are impossible for classical vibration systems and are necessary for automated vibroacoustic control of buildings and structures and ensure the safety of their operation. The use of reduced bit depth coefficients in the calculation scheme using the Jack W. Crenshaw algorithm is justified in a wider range of argument values than with initial coefficient values for controlling vibration systems with limited computational performance. This is necessary when creating executive bodies of modern systems for automated vibroacoustic monitoring of the cracks and violations of the homogeneity of load-bearing structures of buildings and structures. The oscillation exciter has been tested in laboratory conditions. Scientific novelty. New methods and algorithms for automatic control of vibration exciters have been developed to obtain polyfrequency oscillations, linear waves and wave fields with specified amplitude and frequency characteristics. Practical significance. An oscillation exciter has been developed for a system of automated vibroacoustic control of the buildings and structures operation safety. This provides a necessary and sufficient basis for improving methods for assessing changes in the environment as a result of the appearance of cracks and loss of homogeneity.

IDENTIFICATION OF HIDDEN DAMAGE IN CONSTRUCTIVE ELEMENTS OF BUILDINGS AND STRUCTURES TO REDUCE THE RISKS OF THEIR DESTRUCTION

Problem statement. In emergency situations, which are activated by dynamic impacts from explosions, fires and earthquakes, it is necessary to monitor the stability of objects to assess their suitability for further operation. Purpose of the study. ensuring the safe operation of buildings and structures using methods, software and technical means for vibroacoustic monitoring of hidden damage in building structures. Methods. Analysis and generalization of data, computer modeling, experimental studies of the structures stability using the vibroacoustic method. Research results. Considered: loss of concrete stability, reinforced concrete, bricks and other elements of load-bearing structures; risk factors manifested in the gradual weakening of load-bearing building structures due to the accumulation of internal damage. Sudden loss of stability of structures occurs after the accumulation of a critical amount of damage in structural elements or the rapid growth of cracks, which are activated by the sudden unloading of extremely stressed structures as a result of any dynamic influences. By modeling the destruction process using the finite element method, it has been established that long before cracks on the surfaces of structures can be visually identified, zones of hidden damage can actively spread inside the wall structures of buildings. The main parameters for monitoring the condition of buildings and structures using visual and vibroacoustic methods have been determined. Due to the fact that the object of research is the partial destruction of buildings and structures (that is, not the root cause, but the consequences of the influence of a complex of negative main factors), two main groups of risk factors for assess the risks of stability loss have been proposed. The first group is associated with the detection of external structural damage identified by visual inspection methods. The second group is associated with the detection of hidden damage, the parameters of which are determined by the vibroacoustic method. The integral risk of stability loss is determined by comparing and selecting the maximum risk in the group. Scientific novelty. The methodology for identifying hidden damage in structural elements of buildings and structures has been further developed, which is distinguished by taking into account the parameters of vibroacoustic control of the destruction consequences and assessing the risks of the structures stability loss. Practical significance. The research results make it possible to improve the method for assessing changes in the structure of the medium as a result of the occurrence of observed and hidden systems of cracks using vibroacoustic monitoring.

Влияние режима пожара на огнестойкость несущих строительных конструкций машинных залов ГРЭС

Machine rooms of a state district power plant (GRES) are sizeable. Heat impact on the structures of the building in the case of a real fire can significantly differ from the impact in the case of a standard fire. Therefore, the calculation of fire resistance of building structures should be conducted not only in conditions of a standard fire but of a real fire as well. The objective of the study is the theoretical evaluation of the actual limits of fire resistance of load-bearing building structures of the machine room of the main building of the Nizhneturinskaya GRES in conditions of standard and real fire regimes. Numerical experiments to calculate the heating of load-bearing building structures in the case of a standard fire and the case of the most hazardous scenario of the real fire development have been conducted in the framework of the study. A field 3-dimensional model to calculate fire hazardous factors and a non-stationary thermal conductivity equation have been applied. The obtained results have been analyzed. The field model adapted to the space-planning solutions of the machine room has been described. The most hazardous scenario of the development of real fire in case of combustion of the turbine oil spill in the sector of the machine room with the lowest height of ceiling has been chosen. The temperature fields in the gaseous environment of the machine room at different moments are presented. It has been detected that the heating of reinforced concrete structures of the machine room ceiling is significantly uneven due to the 3-dimensional gas dynamic pattern of fire. Dependencies of temperatures of the frame of reinforced concrete load-bearing structures of the ceiling on the time of standard and real fires in the most heated section of the ceiling have been obtained. It has been determined that the maximum temperature of the frame in the case of the standard fire is lower than in the case of real fire. Due to the features of the 3-dimensional thermal gas dynamic pattern of fire in machine rooms of the GRES, the fire resistance of load-bearing building structures in these premises must be determined in both conditions of standard fire and real fire, considering the most hazardous scenario of its development.

Математичне моделювання динамічних впливів на будівельні конструкції

The solution of the problem of mathematical modeling of dynamic influences on building structures is considered in general and in connection with important scientific and practical tasks. In modern conditions, special attention should be paid to the problems of taking into account dynamic influences, parameters of load-bearing structures of buildings that affect their structural reliability and safety. For many years, information about catastrophic destruction of buildings and structures has been appearing more often, which are the result not only of errors that arose during the construction of facilities, but also due to dynamic influences that arose during their operation. A buildable technical system will be used in advance with the technical parameters set, which is responsible for the control of the process of the preparation of structures, the installation of the equipment, during the operation and operation. The development will be carried out and the sporud will be constantly used to promote the development of future technologies, the development and the establishment of the future, as well as the development of dynamic developments in the future. In particular, it is important to understand the development of the engineering and geological minds of the spores, as they have known the front deformation of the non-essential axis of the runt foundations. Various methods are used for structural dynamics, such as modal analysis, response spectrum analysis, time analysis, and finite element analysis. These methods include mathematical modeling, numerical simulation, and computational methods to predict the behavior and response of a structure under dynamic load conditions. Knowing the frequency and form of the structure, it is possible to estimate the dynamic reaction of the design to the application. For the purpose of including the transfer of the world, the destruction of internal forces in the real parts of the construction. Analyses of the response to the additional assessment of the characteristics of the construction, the identification of critical areas and the re-conversion, which the project is able to meet the criteria.

Stress-strain modelling for a composite reinforced concrete beam

The study is aimed at the features of modeling the stress-strain state of a concrete beam, reinforced with two types of fibrous composites. The necessity of strengthening existing reinforced concrete structures can be caused by the reconstruction or technical re-equipment, which often entails an increase in the load on the load-bearing structures of buildings and facilities, as well as during the elimination of the consequences of factors that led to a decrease in the bearing capacity or a failure of loadbearing structures. In order to study the applicability of the model, we analysed the results, obtained during bending and axial compression tests of T-section reinforced concrete beam specimens with welded frame reinforcement that were in operation and the results of a numerical study in a LIRA software suite. The stress-strain state of specimens was modelled in a nonlinear formulation using the finite element method. The conducted analysis and theoretical studies have shown the applicability of models, developed based on a limited test database, unclear, especially with regard to a wide range of compression coefficients, while the results of modeling the behavior of reinforced concrete beams have demonstrated sufficient accuracy for applying in the strengthening design using external composite reinforcement.

Comparison of ultrasonic and GPR methods for investigation of reinforced concrete columns

The presence of internal concreting defects such as pores, cavities, sinks, in load-bearing vertical structures can lead to serious consequences, up to accidents. In this regard, it is especially important to identify such defects is an important and relevant task during surveys of load-bearing structures of buildings and structures. At the same time, the search for internal defects is complicated by the fact that they may not be visible on the surface, but may be present in the body of structures. In order to control the quality of the erected monolithic structures, their instrumental examination is carried out with the identification of the possible presence of internal defects by the method of through ultrasonic sounding. The article discusses the comparison of ultrasonic and GPR methods for searching for internal defects in concreting reinforced concrete columns. The studies were carried out on real construction sites in which there were suspicions of internal defects in concreting of high columns. Conclusions are drawn about the possibilities and limitations of the methods. The resolution limits of the methods are presented. The results of the conducted studies show that, despite the relative modern popularity of ground-penetrating radar, ultrasonic methods can work equally well in this type of specific research scenario and have shown a high potential to overcome some inherent limitations of ground-penetrating radar when working with saturated reinforcement.

Применение системы мониторинга технического состояния конструкций покрытия опасных производственных объектов машиностроительной промышленности

The article presents data on the implementation of technical monitoring using the engineering structures monitoring system (SMIC) for the technical condition of the load-bearing building structures covering the Main Building of JSC "DMZ". The monitoring of the workshop coating elements was carried out after a complex of instrumental surveys with the strengthening of individual building structures, general geodetic monitoring with subsequent strengthening of crisis structures.

Studying the Efficiency of Composite Longitudinal and Transverse Reinforcement for Increasing the Strength and Rigidity of Flexible Eccentrically Compressed Reinforced Concrete Poles

Introduction. In recent years, the use of composite materials for improving the operational properties of the building constructions within the restoration process is gradually replacing the methods, developed for this purpose in the middle of the XXth century and implying the use of reinforced concrete and metal. However, the regulatory framework stipulating the process of strengthening the loadbearing structures of buildings and structures was developed based on the insufficient amount of experimental data. Due to this fact, the large number of structures, exceeding the normative limits, cannot be strengthened with the composite materials, or such strengthening incurs significant economic costs. Thus, nowadays, the experimental studies on strengthening the reinforced concrete structures with composite materials are considered to be forward-looking and relevant. The aim of this study is to analyse the results of a number of experiments conducted to investigate the use and efficiency of composite materials in construction. Materials and Methods. To determine the level of stress in composite carbon materials of the external reinforcement of the eccentrically compressed reinforced concrete poles, the tests were carried out with four specimens. All specimens were strengthened using different reinforcement schemes. The strain gauges with 2cm active measuring grid length were installed in the zones of the most evident work of the composite materials to measure the changes of relative deformation at each load level during testing of the specimens. From 10 to 16 strain gauges were installed at each structure, depending on the importance of the zones for determining the deformations.Results. The work presents the results of the study on determining the efficiency of composite longitudinal and transverse reinforcement for increasing the rigidity and strength of flexible eccentrically compressed reinforced concrete poles. The experimental data on the composite materials’ strength, deflections and relative deformations, obtained during testing of four reinforced concrete poles, is presented. The efficiency of composite reinforcement at ultimate strength and ultimate deflections is assessed. The relative deformations in composite materials are determined and the inclusion of the reinforcement system in the work of the strengthened reinforced concrete specimens is assessed.Discussion and Conclusion. Based on the obtained results, the analysis of the composite reinforcement efficiency has been carried out, and proposals have been developed on designing the reinforcement systems of the flexible eccentrically compressed reinforced concrete poles working with the large eccentricities of the load application.

The pavilion “Petite Maison” of the European Cultural Capital Esch'22: A case study of circular economy benefits in steel construction

Abstract“Petite Maison” is a collaborative architectural project on the theme of circularity in construction within the Esch2022, European Capital of Culture, in Luxembourg. Focusing on a similar concept, the RFCS project “REDUCE” has previously worked out the structural and environmental analysis of a modularized construction approach to evaluate and highlight the benefits of a reusable, circular steel structure. As a follow up to this project, CoCo Project (Carbon Counting and Projection) currently occupies with the determination of suitable routes to point out low‐carbon emission scenarios for the construction sector considering especially steel and steel composite solutions as well as prefabricated structural elements, which may be in concrete or timber. In other words, the project aims to demonstrate the impact of circular economy objectives in the load bearing building structures, considering majorly columns and flooring solutions containing concrete slabs, Laminated Veneer Lumber (LVL), and steel beams. In this article, the environmental performance of Petite Maison flooring system, as a case study, is investigated in detail. Different scenarios are defined for steel elements to quantify the environmental impacts and to emphasise the benefits of modular and reusable structural components.

ДВУТАВРОВЫЕ ГНУТОСВАРНЫЕ ПРОФИЛИ С ПЕРФОРИРОВАННЫМИ СТЕНКАМИ И РАСЧЕТ ИХ ОПТИМАЛЬНЫХ КОМПОНОВОК

A new technical solution of I-beam bent-welded profiles with perforated stacks and shelves with closed welds is presented. Each of the inclined faces of the shelves in cross-section has the shape of half a round halfring (a circle) with a radius equal to the height of the shelves. The maximum height of the cutouts is limited by the height of the single wall. The calculation of optimal parameters along the middle line of a thin-walled cross-section of an I-beam shape with a single wall and closed (tubular) shelves is given. As a double optimization criterion, the maximum of the moment of resistance of the section in the force plane of the supporting structure and the maximum height of the cutouts in the perforated wall. According to the results of solving the optimization problem, the moment of resistance and the height of the cutouts are maximal when this height reaches 0.84 of the entire height of the profile, and the ratio of the width and height dimensions is 1/6,4. The optimization calculation is supplemented by the calculation of the deflection of the punch using the reduced moment of inertia of the section, determined from the equality of the areas of the calculated and conditional plots. A comparative analysis of the design parameters of I-beam rolled and bent-welded profiles with perforated the main results of which revealed a noticeable increase in the mounting (lateral) rigidity of the new modification and confirmed the prospects of its use in load-bearing structures of buildings and structures.

Features of measuring deformations of load-bearing structures of buildings during their field and laboratory tests under the action of static and dynamic loads

The peculiarities of measuring the deformations of load-bearing structures of buildings during their field and laboratory tests using strain gauge-based sensors are considered. An overview of various problematic issues that arise in the process of conducting experimental tests and affect the measurement results is given. The most common, which affect the accuracy of measurements, are the effects of temperature, humidity, and vibration; the difficulty of calibrating and mounting strain gauges on different surfaces of elements; complexity of measurement data processing; combination of high-quality work of strain gauges, cable conductors, measuring equipment, data collection and processing system; the selection of the connection scheme of tensor resistors in the Wheatstone bridge. The peculiarities of the organization of the experiment for testing the load-bearing structures of the building, namely pile foundations, are considered, and the main problematic issues when using strain gauges as strain gauges of building elements are given. The use of strain gauges to measure deformations of load-bearing structures of buildings is one of the common methods, which has many advantages, which are discussed in detail in the work. Strain gauges can be used to measure deformations of elements that are mechanically connected to them. They have high measurement accuracy, sensitivity to element deformation, and a wide variable measurement range. The advantages of using the Wheatstone bridge to measure the change in electrical resistance are highlighted, as this method allows measuring very small values of the change in resistance. Methods of connecting tensor resistors according to the Wheatstone scheme are considered, the choice of which depends on the purpose of the study and the required accuracy. One of the easiest ways is to connect just one strain gauge to a current or voltage source and measure the change in resistance. But this method has low sensitivity and does not compensate for the effect of temperature. A more accurate way is to connect two or four tensor resistors in the Wheatstone bridge circuit, which allows you to measure the voltage change on the diagonal of the bridge. The bridge circuit has a high sensitivity and can compensate for the effect of temperature if the tensor resistors have the same coefficient of temperature dependence of the resistance. An algorithm for measuring the deformations of a metal pipe working under compression using strain gauges has been developed.

WAYS TO IMPROVE THE ENERGY EFFICIENCY OF PIPELINES AND STRUCTURES USING AEROGEL

Problem statement. The paper explores ways of energy saving in buildings, namely, the compliance of the regulatory framework with European standards, the possibilities of reducing heat losses during the transportation of energy carriers through pipelines on the example of heat supply systems and reducing heat losses during the operation of buildings and structures. The second part of the article presents the results of analytical studies of various heat-insulating materials that are most commonly used in Ukraine. Some of these materials cannot be used on structures and pipelines of complex configuration. The issue of energy efficiency, along with improving sound insulation properties, reducing fire hazard, and reducing loads on the load-bearing structures of buildings and structures, can be addressed by using aerogels as a thermal insulation material. The material is characterized by a low dependence of the thermal conductivity coefficient on changes in ambient temperature, which makes it the best option for use in harsh operating conditions. The purpose of the article is to consider ways to improve the energy efficiency of structures and pipelines using modern aerogel insulation material. Conclusions. Having conducted analytical studies of various thermal insulation materials, it was found that aerogels in roll form, in addition to a low heat transfer coefficient, are characterized by better performance properties, namely non-flammability of the material, environmental safety, low weight, which reduces the load on structures, ease of installation, the possibility of using for structures of complex configuration, and a high rate of sound insulation.

Comparison of efficiency for steel and combined frames

Recently, in the practice of design, customers of design works and investors of various projects have a dilemma regarding the choice of building material for load-bearing building structures. At the same time, the choice is usually limited to two types of materials – steel and reinforced concrete. Each of these materials has its advantages and disadvantages, which results in their different efficiency of application for various types of building structures. At the same time, the main attention is paid to the estimation side, because in modern complex and dynamic conditions, it turns out to be dominant in many cases. 
 The article presents the results of research of the completed master's thesis on the comparative analysis of the effectiveness of steel and combined frames (steel-reinforced concrete) on the example of the filter station building. The building has dimensions in plan of 54 × 36 m with a total height of about 22 m. Its supporting frame is a statically nondefined flat frame consisting of columns and crossbars in the form of trusses. In the longitudinal direction of the building, the frames are united into a spatial system by means of covering structures. The building is craneless and has three floors, each about 6.5 m high. 
 In the course of research, the considered variants of the transverse frame were analyzed using the finite element method on the basis of the LIRA-CAD multifunctional design complex. As a result, appropriate cross-sections for loads according to the climatic conditions of Ukraine were obtained. A comparison of variants showed that the first design variant is 9 % cheaper. Taking into account the additional technological advantages in its manufacture, the steel frame can be considered more effective for the given construction conditions and be recommended for practical implementation. Separately, it should be noted that such a frame also has an average of 5 times less total mass, which should be considered its additional advantage.

Evaluation of Effectiveness on Some Vibration Isolation Methods for Existing Buildings and Structures from Vibrodynamic Effects, Propagating in Soil Environment

The paper presents calculations of various design schemes for vibration isolation of a building with a reinforced concrete frame from a source of vibrodynamic exposure located outside it. It is noted that in most studies, the maximum value of the velocity of vertical vibrations of the foundation or soil in front of it is used as a criterion for the risk of damage to load-bearing building structures. The main factors that determine the risk of damage to structures are identified. These include the engineering and geological conditions of the soil at the base of the affected foundations, the degree of damage to the building, the type and design of the building or structure, the vibration frequency, the duration of the vibration, the distance to the vibration source, the type of vibration source, the material of the structure and the type of foundation. Based on the analysis of factors that determine the risk of damage to structures, the parameters of a building or structure that are least sensitive to vibrodynamic effects and have greater operational reliability are identified. It should be with a frame made of reinforced concrete or steel, not damaged, located on foundations of pile-racks in strong, low-moisture coarse sands or hard clays. The proposed design schemes for vibration isolation are mainly based on one of the vibration damping mechanisms in the soil medium – scattering on inhomogeneities. The finite element method has been used as the main tool for theoretical research. The ground medium has been considered as an elastic inertial array bounded by non-reflecting boundaries. The reliability of its application for calculating the development of dynamic processes in the system “oscillation source – propagation medium – oscillation receiver” has been confirmed by verification based on data from small-scale laboratory experiments. The use of the finite element method (FEM) makes it possible to take into account the spatial variability of soil conditions, the properties of materials, the design features of buildings and structures, the magnitude, direction and point of application of the dynamic load, as well as to model and optimize various vibration protection schemes. Seven variants of vibration isolation have been considered: the device of an inertial slab on the surface of the soil medium between the vibration source and the building, the installation of a vertical screen from gas-filled cylinders under pressure, a combination of these methods, the installation of a pile field in the soil medium, the reinforcement of the columnar slab foundations of the building with micropiles, the installation of a ribbed slab on the surface soil environment between the source and receiver of oscillations, the device of a reinforced concrete cage around the foundation-source of oscillations. The effectiveness of each method of vibration isolation has been evaluated by the damping coefficient K, a parameter showing how many times the speed of vertical oscillations of the building foundation decreases. Among the above methods of vibration isolation, two most effective options have been identified: in the form of a horizontal inertial slab of reinforced concrete on the surface of a soil mass (4.5-fold reduction in the rate of vertical vibrations), and a vertical barrier made of pressurized gas-filled cylinders (reduction in the rate of vertical vibrations by 3.32 times).

Датчик линейных перемещений для мониторинга инженерных конструкций зданий и сооружений

The article provides an analysis of techniques and devices used in monitoring and evaluating the parameters of the stress-strain state of load-bearing structures of buildings and structures. The prototype and the principle of operation of converters for measuring linear displacements under dynamic loads are described. The description of a new innovative linear sensor developed on the basis of an "electro-chemical converter" is given. At the end of the article, the tasks and directions of further research are given.