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  • Reducing the concentration of fine dust PM2.5 and PM10 in construction by optimizing facilities on the construction site

    In most countries of the world, the construction industry is one of the main sources of air pollution in urban areas and agglomerations. One of the most dangerous pollutants are fine dust particles PM2.5 and PM10, formed from the production of dusty construction processes. Due to the optimal location of administrative facilities on the construction site, it is possible to reduce the concentration of dust emissions of particles PM2.5 and PM10. In addition, the cost of the dust control method is of concern to contractors, as it leads to an increase in the cost of construction. Therefore, reducing overall transportation costs is another optimization goal. To solve several tasks at once, the study uses multi-purpose optimization using the particle swarm method (MRF) algorithm to find an optimized construction site layout that can simultaneously reduce both the level of pollution from dust emissions and transportation costs.

    Keywords: environmental safety, environmental monitoring, atmospheric air protection, ecology in construction, dust suppression, feasibility study, dust collection systems, labor protection in construction

  • Analytical representation and analysis of loose knots in the course of the calculation of the maximum possible fire load

    We have considered the improvement of analytical formulas for the determination of bending moments in a single-span beam with semi-rigid nodes. We have obtained analytical relationships for deflections, angles of rotation, bending moments and shear forces in a single-span beam with semi-rigid nodes. A convenient coefficient from 0 to 1 is used to specify the intermediate stiffness node. The coefficient characterizes the fraction of possible rotation of the support node. When we derived the formulas, we used the assumption of constant bending stiffness of the beam along its length and linear deformation of the beam material under load. We did not consider the cases of loading the beam with concentrated forces and concentrated bending moments in the span. We realize the complexity and necessity of calculating beams with semi-rigid nodes, so we have created a table for easy calculation. In the table you will find the values of the supporting moments depending on the degree of possible angle rotation. With the information about the bearing moments, you can load the hinged beam with them and construct a bending moment diagram. The upper left and lower left values from the table are used to determine the bending moments at the supports. The upper right and lower right values of the table are used to determine the bending moments in the beam span.

    Keywords: semi-rigid nodes, multilayer structures, calculation methods, contact zone, wooden beams, reinforcement, wood, reinforcement, environmental friendliness

  • Managing the construction process with a digital construction organization project

    This paper analyzes the shortcomings of the existing organizational and technological documentation, namely the construction organization project and the project of work production. It is concluded that the main task of organizational-technological documentation is to minimize construction risks at the earliest stage, to increase knowledge about the project and to transfer the process of development and decision-making to an earlier stage of construction. As a solution to these problems, it is proposed to consider the use of building information modeling technologies (BIM) in construction, and move to the development of digital construction organization project (4D model of the construction process), which is a digital information model of the capital construction object (3D model), the elements of which are interconnected with the work on construction production. Two projects where the building information modeling technology was applied and a digital construction organization project was developed are considered: construction of an underground tunnel and reconstruction of a power unit of a combined heat and power plant. The advantages of using a digital construction organization project are proved, which makes it possible to forecast the planned duration of works, as well as the duration of works, taking into account the occurrence of risk events, necessary resources and equipment.

    Keywords: digital project of construction organization, 4D model, building information modeling, project of construction organization, capital construction object

  • Methodology for contact zone shear testing using tensile and compressive loading

    The article deals with the peculiarities of the study objectives and test methodology for characterization of different contact zones organized in different ways and requiring different methodological approach for specimen fabrication and testing. The steel plate-concrete contact zone organized by stamping on the steel plate requires the use of steel molds to prohibit horizontal movement. The contact zone between the steel plate and the concrete, organized by the stamping on the steel plate requires the use of steel molds to prohibit horizontal movement. The contact zone of two wooden bars organized by epoxy glue with reinforcing fabric placed between the layers of glue is tested for shear without organizing the prohibition of horizontal movement. The contact zone formed at the connection of a steel plate and incompletely gained strength concrete, with the association of steel bars has features of fixing the actual strength of the concrete part of the specimen. The considered methods have both a number of common features and differences, which are taken into account in the proposed methods of fabrication and testing.

    Keywords: contact zone, contact characteristics, test methodology, shear tests, stamping, composite construction

  • Architecture and model of an agricultural wireless sensor network

    The paper describes the composition of a wireless sensor network for agricultural purposes, including a sensor node, an actuator node and a coordinator node. Based on the IEEE 802.15.4 standard, a hybrid network architecture with node synchronization via a time slot mechanism is proposed. The WSN model is proposed, which includes the forming functions of nodes, which makes it possible to abandon the matrix of energy characteristics and describe the elements of the network in a simplified form.

    Keywords: wireless sensor network, sensor node, coordinator node, network structure, wireless node architecture, wireless network parameters, network model

  • Issues of sufficiency of engineering and geological surveys on the part-time territory for the installation of the foundations of power floors and foundations of the logistics center

    The loads on the power floors and column foundations of modern logistics centers can reach 6-9 t/m2 and 1000 t, respectively. At the same time, the step of the grid of exploration wells in the mined areas does not allow reflecting on the geological sections the exact geometry of the occurrence of weak, untreated soils of backfilling pits. The use of a method for strengthening man-made soils by pressing in prefabricated prismatic piles made it possible to compensate for the missing information from engineering and geological surveys by controlling the forces of indentation and thus determining the occurrence marks of more durable foundation soils.

    Keywords: engineering and geological surveys, the territory being worked on, man-made soils, soil reinforcement with piles, geological section

  • Hybrid method of dynamic packet routing in a wireless sensor network

    The paper proposes a hybrid method of packet routing in a wireless sensor network based on a genetic algorithm that allows you to build a routing table taking into account restrictions on the maximum number of transmissions through each node of the network and, as a result, increase its energy efficiency. The results of experimental studies on BSS with a random configuration of nodes in space are presented and it is shown that the congestion of data packet relay nodes is reduced by 30-40% with an increase in the total length of routes by 10%.

    Keywords: wireless sensor network, sensor node, coordinator node, network structure, packet routing, energy efficiency of a wireless network, network model

  • Punching shear strength under static and dynamic loads

    Modern domestic calculation methods and developed countries for determining the bearing capacity of monolithic reinforced concrete slabs for punching do not fully take into account all factors of design solutions and operating conditions. The available design provisions are made for the static operation of structures and there are no recommendations for taking into account the features of the dynamic impact on the overlap and the nature of the work of the node interfaces. The accepted empirical assumptions of the calculation, based on numerous experimental data, do not take into account the features of the stress-strain state of the coupling of the overlap with the column during destruction according to the punching scheme. This is due to the lack of computational models in which all the acting internal forces ensuring the resistance of the interface to penetration would be considered comprehensively. The complexity of the problem is due to the fact that the sections of the nodal interface are in an inhomogeneous stressed state. The stress-strain state of plates for punching under dynamic load is currently little studied. This article proposes a method for determining the bearing capacity of a symmetrical nodal coupling of a column with an overlap for punching under static and short-term dynamic loading. The proposed design model of the punching strength is based on the following prerequisites: the resistance to punching of a monolithic reinforced floor consists of the shear resistance along the surface of the reduced punching pyramid formed by the height of the compressed concrete zone; the strength of the concrete shear resistance increases due to volumetric compressive forces on the surface of the reduced punching pyramid; the angle of inclination of the faces of the punching pyramid depends on the loading speed. The obtained theoretical dependences are applicable under static and dynamic loading and are in satisfactory agreement with experimental data.problems in the field of video analytics. Numerous studies have shown that, despite the dynamism of processes in the field of information technology and the introduction of various tools and methods, the task of object maintenance still remains relevant and requires further improvement of previously developed algorithms in order to eliminate some inherent disadvantages of these algorithms, systematization of techniques and methods and the development of new systems and approaches. The presented article describes the process of step-by-step development of an algorithm for tracking human movements in a video stream based on the analysis of color groups. The key stages of this algorithm are: the selection of certain frames when dividing the video stream, the selection of the object under study, which is further subjected to a digital processing procedure, the basis of which is to obtain information about color groups, their average values and percentages of their occupancy relative to the object under study. This information is used for the procedure of searching, detecting and recognizing the selected object with an additional function of predicting the direction of movement on video frames, the result of which is the formation of the entire picture of the movement of the person under study. The materials presented in this paper may be of interest to specialists whose research focuses on issues related to the automated acquisition of certain data in the analysis of various images and videos.

    Keywords: coupling of a monolithic floor with a column, static and dynamic load, punching pyramid, tangential stresses, concrete shear strength, punching strength

  • A new approach to assessing the contamination level with heavy metals in the soil-like fraction from landfills

    The paper presents a new approach to assessing the level of contamination with heavy metals of the soil-like fraction from landfills using Monte Carlo simulation using the example of landfills located within the borders of Volgograd.It was found that with a probability of 36.2%, the contamination level of a soil-like fraction from the landfill located in the Voroshilovsky district will correspond to moderately hazardous, and with a probability of 63.8%, hazardous. It is economically justified to isolate a soil-like fraction with a low level of pollution to detoxify it and further use it in the territory reclamation. For a soil-like fraction from landfill located in the Traktorozavodsky district, the pollution level was determined as extremely hazardous and hazardous with a probability of 87.1% and 3.1%, respectively. It is shown that a useful and usable part cannot be isolated from a soil-like fraction. A soil-like fraction must be neutralized and placed at waste disposal facilities.The presented approach is a useful instrument for pollution level assessment of a soil-like fraction, which can increase the accuracy of an estimate and the management effectiveness of a soil-like fraction during landfill development.

    Keywords: landfill, soil-like fraction, heavy metals, pollution level, Monte Carlo method, modeling

  • Influence of recycled aggregate based on concrete scrap on the properties of concrete

    The influence of secondary crushed stone on the strength and shrinkage of concrete was studied. The results showed that when granite coarse aggregate is replaced with crushed recycled concrete, the compressive strength of concrete is reduced by an average of 20% and the flexural strength by 3-10%. Concrete on recycled crushed stone has a high shrinkage. The shrinkage of concrete with a minimum consumption of recycled aggregate differs slightly from the shrinkage of concrete on granite crushed stone.

    Keywords: demolition waste, concrete scrap, recycling, recycled aggregate, compressive strength, flexural strength, shrinkage

  • Study of the reliability of an oil pipeline operated in extreme conditions of the Far North

    Reliable and safe operation of oil and gas pipelines in the conditions of the Far North and Siberia is an urgent task facing the Russian Federation. It has the most important economic and strategic importance. The climatic and geological conditions of these regions suggest a high degree of risk associated largely with seasonal temperature fluctuations and oil pumping technologies, leading to freezing or thawing of the soil, the appearance of thawed permafrost waters. The purpose of our study was to analyze the influence of extreme natural and operational conditions on the design and spatial position of pipelines during the operation of the section of the CPS-2 - NPS Urengoyskaya highway. It was found out that the studied section of the oil pipeline has a predisposition to failures due to unfavorable conditions: meltwater, heaving soils, swampy territory. Technological calculations allowed us to conclude that at this stage the pipeline route meets all the conditions of strength and stability, i.e. the reliability of the pipeline is ensured.

    Keywords: hydrocarbons, pipeline, melt water, underground laying, strength calculation, stability calculation, permafrost soils, spatial location

  • Information modeling of a complex-shaped building frame using an Autodesk CFD PC

    The article considers the information modeling of the building frame of a complex shape in the plan. The Dynamo program for Autodesk Revit is used to build the geometry. The main goal was to achieve uniform color pressure maps when blowing a building using simulation modeling in an Autodesk CFD PC. The research method is numerical (finite element method). The LIRA-CAD software package was used. The finite element method was used to select the shape of the building and adjust its design scheme to achieve reliability and efficiency. The analysis of the structural elements of the object on the effect of wind loads, taking into account the pulsation component of the wind load, is carried out in order to improve the design decisions made.

    Keywords: information modeling, finite element method, building frame, node system, modal analysis, waveforms

  • Environment under the influence of motor transport in the coastal zone of the city of Volgograd

    The article provides overview information on the importance of ensuring the environmental safety of environmental sulfur, on factors designed to counter the adverse effects of pollutants on the urban environment, aimed at creating comfortable living conditions for the population, and protecting the living environment from the harmful effects of transport. Information is provided on trends in increasing the anthropogenic impact of greenhouse pollution on climate change, Decree of the President of the Russian Federation (dated October 26, 2023 No. 812) on the approval of the climate doctrine, which will be the direction for further research into greenhouse pollution from motor vehicles, data from background stations of the Russian Federation are presented on the increment of CO2 concentrations in the surface layer and in the atmosphere, on the volume of greenhouse gases from the transport flow. Motor transport is indicated as the most influential factor in urban environmental pollution and the negative impact of polluted air on public health in Volgograd. The results of field studies of the intensity of vehicle traffic along the newly commissioned highway “0-th Longitudinal” in Volgograd are presented, a trend of growth in overall intensity, starting from 2019, and an increase in the intensity of low-capacity public transport along newly designed routes are revealed. The directions of necessary research to reduce the environmental impact on the ecology of the coastal zone are shown.

    Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production

  • Experimental planning for the perpendicular shear test of the embossment

    The article deals with the improvement of structural solutions of steel reinforced concrete slabs with external reinforcement. The possibility of creating an orthotropic steel reinforced concrete slab on a profiled deck with a continuous or discrete puff located perpendicular to the direction of corrugations is determined. This kind of construction works in bending in two directions along the wave and across the wave. This will allow slabs to be supported on three and four sides, which will make it possible to redistribute the pressure on the supports and reduce the stress concentration at the joints between the slab and the support structure. A continuous puff is assumed to have the same cross-section along its entire length, while a discrete puff can have a variable thickness. Two variants of the calculation of this structure are found, as a monolithic rod with a sprengel chain and as a composite rod with an explicit contact zone. When the stiffness of the contact zone is close to absolute, the rod can be considered as a monolithic rod. An experimental study of the characteristics of the contact zone of the profiled deck organised by means of stamping on the inner side of the corrugation is required, taking into account the perpendicular location of the corrugations to the span of the beam and the concrete part of the section. A comparative analysis of the existing techniques has been made and further experimental investigation methodology has been determined. A numerical evaluation of stresses in a steel plate has been carried out.

    Keywords: steel reinforced concrete slabs, orthotropic slabs, calculation methods, contact zone, stamping

  • The effect of redispersible polymer powders and holding conditions on the shrinkage of building mortars

    The influence of the type and dosage of some redispersible polymer powders on the shrinkage deformation of building mortars obtained from dry building mixes, including for underfloor heating, after exposure at a temperature of 70 ° C in accordance with GOST R 56387-2018 was investigated. The introduction of admixtures 4042N, E06RA, 5603 into the mixtures did not lead to an increase in shrinkage deformations when maintained according to GOST R 56387-2018 relative to the additive-free standard, regardless of the type and dosage of the admixture, while with these admixtures, regardless of their dosage, within 1-3%, the values of shrinkage deformations were less than 1.5 mm / m. The greatest influence of the type and dosage of the redispersed polymer powders on the shrinkage change is manifested at the heating stage, which is due to their influence on the kinetics of dehydration and the magnitude of the E-modulus. Depending on the type of cement, type and dosage of the admixture, the moisture loss values by the end of heating to 70oC ranged from 0.114 to 0.629 relative to the total moisture loss by the end of holding. Naturally, a change in shrinkage by the end of heating from 0.027 to 0.595 relative to complete shrinkage by the end of aging was noted, while a proportional relationship between moisture loss and shrinkage was revealed. In some formulations, an expansion of up to 0.469 mm/m was recorded by the end of heating. For a comprehensive assessment of the degree of influence of admixtures on changes in the deformation and strength properties of mortar at a holding temperature of 70 ° C according to GOST R 56387-2018, an indicator of the conditional stress level is proposed, varying depending on the holding stage, type of cement, type and dosage of the additive in the range from 0.489 to 3.05.

    Keywords: Shrinkage, building mortars, dry building mixes, redispersible polymer powders, underfloor heating