Problem Of Construction Research Articles

Increasing the reliability of oil and gas well fastening with polycomponent plugging systems

Purpose. Development of effective composite plugging systems for reliable fastening of oil and gas wells in difficult mining-geological conditions of deposits of Ukraine. Methods. The proposed research is based on an analytical and industrial study of the problems of the well construction and fastening in the conditions of chemogenic deposit occurrence when applying the analysis of geophysical research materials. The research of tamponage solutions and buffer liquids was carried out using standard devices and methods that meet the set of requirements for testing cements and technological systems for well construction. Processing of research results was carried out in MATHSAD and EXCEL. Composite cement CEM V according to the European standard EN 197-1, tamponage cement 1-G, krents - high-basic C2F CaSO4 and low-basic 3(CF) CaSO4 calcium sulfoferites were used for the research. Findings. It was established that the basic plugging material, as well as technological solutions for fastening wells in difficult mining-geological conditions, do not ensure compliance of the well as an engineering structure with operational reliability indicators. As a result, violations in the fastening system are quite often recorded, which require significant time and financial costs for their elimination, and sometimes lead to well liquidation. In order to increase the reliability of fastening wells, it is necessary to use multi-component tamponade systems modified by krents. Calcium sulfoferrite admixtures have been proved to accelerate the kinetics of early strength and contribute to the formation of cement stone with improved characteristics. The need to use effective buffer systems to improve the quality of fastening is substantiated. Originality. On the basis of assessment, systematization and detailed study of geophysical material and features of well fastening under the conditions of exposure to chemogenic sediments, the necessity of using composite plugging material was established. The conducted studies have proved that to ensure reliable fastening of wells in difficult mining-geological conditions, it is necessary to use multicomponent composite plugging material modified by calcium sulfoferites with accelerated kinetics of early strength, which form cement stone with a densely packed structure. Practical implications. Based on the industrial material evaluation and detailed laboratory studies, technological solutions have been developed to increase the reliability of well fastening due to the introduction of multi-component composite plugging material modified by krents and buffer liquids.

Research on the Location Selection Problem of Electric Bicycle Battery Exchange Cabinets Based on an Improved Immune Algorithm

The rise of new energy technologies has accelerated progress towards sustainable development, and many companies are beginning to invest in renewable resource-related facilities. Electric bicycles have always been an important mode of green transportation; however, they also have problems such as slow charging, difficult charging, and that burning and short circuiting may occur during charging. Electric bicycle battery exchange cabinets effectively solve these problems by exchanging low batteries with full batteries instead of charging. However, current battery exchange cabinets face the problems of insufficient construction and unreasonable site selection. Therefore, this paper proposes a location selection model for electric bicycle battery exchange cabinets based on point demand theory, aiming to maximize rider satisfaction and the service capacity of exchange cabinets. The immune algorithm is introduced to solve the location model; however, the traditional immune algorithm has some problems such as poor stability and slow convergence. In this paper, the mutation process of the traditional immune algorithm is improved by introducing multi-point mutation, guided mutation, and local search. Finally, based on the data of electric bicycle riders in Shanghai, we verify that the location model based on point demand theory performs well on two objective functions of rider satisfaction and battery exchange cabinet service capability. We also expand the application of point demand theory to location models. Then, by conducting experiments with different parameter groups, through sensitivity analysis and convergence analysis, we verified that the improved immune algorithm performs better than the traditional immune algorithm in its accuracy, search accuracy, stability, and convergence.

Digital Application of BIM Technology in the Architectural Design Stage

This paper discusses the digital application of building information model (BIM) technology in the architectural design stage. Taking the large-scale comprehensive development project of Guangxi headquarters base as an example, this paper analyzes in detail how BIM technology promotes the intelligence and refinement of the design process. Through the three-dimensional modeling and simulation analysis of BIM technology, the project design has realized the accurate transformation from concept to operation, which not only improves the design efficiency, but also ensures the construction quality and economic benefits. This paper focuses on the application of BIM in the digital design of building structure, the deepening design of steel nodes, as well as the remarkable results in the comprehensive layout optimization of mechanical and electrical pipelines. Through the collision detection and optimization design of the BIM model, the potential design conflicts and construction problems were found and solved at the initial stage of the project, ensuring the efficient promotion and smooth implementation of the project. The research results show that BIM technology, as the core digital tool in the architectural design stage, is of great significance for improving the overall design level of the construction industry and realizing intelligent construction.

Сharacteristics of demolition waste management in the regions of Ukraine

The volume of waste left from war-related destruction amounts to 10-12 million tons per year. Such volume is comparable to the annual volume of municipal solid waste generated in Ukraine. This situation led to formation of unauthorized landfills and complicated the existing problem of industrial, consumer, construction and demolition waste management. Consequently, the issue of destruction waste management became a pressing environmental and socio-economic problem. The objective of this research is to assess the characteristics of destruction waste management in the regions of Ukraine. Destruction waste is generated during construction of new buildings and public structures, as well as during renovation or demolition of existing buildings and structures; including general-use facilities. It is estimated that, before the war, nearly 7 million tons of construction and demolition waste was generated annually, with more than 50% being transported to municipal solid waste landfills. Specialized landfills for its disposal were virtually non-existent in the regions of Ukraine, so this waste, despite its resource value, was taken to municipal solid waste landfills or unauthorized dumps. Some components of construction and demolition waste are toxic. Destruction waste includes parts (fragments) of damaged (destroyed) objects, as well as materials and items that were inside or next to such objects at the time of damage (destruction) and/or during disassembly activities, including those that fully or partially lost their consumer properties and cannot be reused at the place of their origin or discovery. Destruction waste pollutes the environment, so one of the ways to reduce environmental risks is to develop an effective waste management system to stop chaotic processes during disassembly activities. Destruction waste differs from construction and demolition waste by the presence of accompanying hazardous components, complicating the development of a waste management system. The main components of destruction waste should be used as secondary raw materials for construction, production of building materials and other purposes. Provided that appropriate physical-geographic, engineering-geological, hydrogeological, technical, and socio-economic conditions are available, it is advisable to create temporary waste storage sites, with their subsequent use as secondary raw materials in the post-war period for restoration of civil, industrial, and transport infrastructure in the regions of Ukraine.

On construction of quality virtual backbone in wireless networks using cooperative communication

An extended connected dominating set (ECDS) in a wireless network with cooperative communication (CC) is a subset of nodes such that its induced subgraph is connected and each node outside the ECDS is covered by either one neighbor or several quasineighbors in the ECDS. Traditionality, the size of virtual backbone (VB) is the only factor considered in the problem of CDS construction. However, diameter is also an important factor to evaluate VB. In this paper we consider the problem of constructing quality ECDSs in unit disk graphs under CC with both of these two factors. We propose a two-phase centralized algorithm BD-ECDS to construct an ECDS for a given UDG with CC, which has a constant performance ratio (PR) and diameter. To obtain the PR of this two-phase centralized algorithm, we first give an upper bound of the EDS and use this upper bound to prove that the size of the ECDS under CC generated by the centralized algorithm is no greater than 120|ECDSopt|−2, where ECDSopt is the size of the minimum ECDS. Furthermore, our theoretical analysis and simulation results show that our algorithm BD-ECDS is superior to previous approaches.

Road Site Inspection and Measures to Avoid Further Deformation

Strength and stability of the roadbed and engineering structures in permafrost conditions and deep seasonal freezing of soils always remain complex scientific, technical and technological problem in construction and reconstruction of roads in northern regions. Particularly important is the spread of subgrade subsidence during construction and further operation and maintenance of roads in these regions. The road destruction is mostly caused by both global warming and geological and hydrogeological conditions.To prevent the deformation development, it is necessary to provide a number of special engineering measures to prevent thawing of permafrost soils or strengthen supra-permafrost layers of foundations. The purpose of the work is to study methods for eliminating deformation of the road bed in permafrost and choosing the main method for eliminating subsidence of the road.The article discusses several ways to solve the problem of eliminating subsidence on of the federal highway. Options for reconstruction of the roadbed are considered. These are different methods of thermal stabilization, i.e., horizontal (sloping) thermal stabilization system with inclined thermal stabilizers, temporary vertical thermal stabilizers for pre-construction freezing of foundation soils, and hybrid thermal stabilization system (horizontal and vertical thermal stabilizer in one product). A method is proposed for stabilizing the road base by installing soil-cement piles. The main advantages of and disadvantages the methods are noted and cost assessment is made. A conclusion is drawn on the effectiveness of different methods to restore the subgrade structure in order to ensure the road base stability. The main method is elimination of subsidence by stabilizing the road base with installation of soil-cement piles.

Blasting safety criterion of existing high speed railway tunnel over tunnel

Drilling and blasting method is still an important method in the current tunnel excavation construction. Controlling the vibration effect of blasting during construction and its influence on the upper span tunnel is the key problem in tunnel construction. Based on Chongqing Science City tunnel excavation blasting project, combined with the tunnel blasting vibration monitoring and testing, this paper analyzes the propagation attenuation law of tunnel blasting vibration along the rock mass, and studies the load characteristics of the explosion stress wave propagating to the existing high-speed railway tunnel. Considering the influence of the buried depth of the blasting source, a mathematical prediction model of the attenuation law of the upper span existing high-speed railway tunnel caused by tunnel blasting is established. Based on the dynamic finite element numerical calculation method, the influence of blasting vibration on the structure of the existing high-speed railway tunnel under construction is analyzed, and the propagation and attenuation law of blasting vibration along the tunnel contour is studied. Based on the ultimate tensile stress criterion, the ultimate shear stress criterion and the Mohr criterion, and compared with the results obtained from the numerical simulation, the blasting safety criterion model of the existing high-speed railway tunnel over the tunnel is established.

Effect of Nanostructured Shungite on the Rheological Properties of Bitumen

Improving the physico-mechanical characteristics of bitumen is a constant and pressing problem in road construction. The issue is solved by modifying bitumen with various additives, one of which is a nanostructured modifier. This paper examines the effect of adding a natural mineral, shungite, to bitumen from the Koksu deposit (Kazakhstan) after grinding under different conditions. The mechanochemical activation of shungite made it possible to obtain samples with an average particle diameter of up to 3 μm. Using scanning electron microscopy, nanostructured particles with sizes of up to 100 nm were discovered in their structure. The effect of nanostructured shungite on the rheological characteristics of bitumen—elasticity and loss moduli, and loss tangent at high and low temperatures—was studied. The transition temperatures of bitumen from the viscoelastic to the liquid state were established, and their shift to the region of elevated temperatures when modified with ground shungite are shown. The presence of organic and inorganic components in the composition of shungite—carbon, silica, and metal oxides—has a beneficial effect on the rheological properties of bitumen by forming bonds with resinous asphaltene components of bitumen. The use of bitumen modified with nanostructured shungite makes it possible to replace the polymer modifier with a natural mineral to improve the quality of the road surface.

Continuous Slag Discharge Construction Technology for Shield Tunneling in Narrow Space Environment

The shield tunneling method is the main construction method in subway tunnel construction, which has the characteristics of safety, efficiency, mechanization, and high degree of automation. However, the shield tunneling equipment is huge, the supporting facilities are numerous, and the site requirements are high. In response to the problems of slow slag removal speed and low construction efficiency in shield tunneling under the construction conditions of small wellhead shield tunneling sections in urban subways, taking the shield tunneling section of Guangzhou Metro Line 13 Phase II as the background,This article introduces the main components, working principles, installation and transportation processes, fault handling, and benefit analysis of the continuous belt conveyor slag removal system,This article elaborates on the method of using a continuous belt conveyor in the tunnel combined with a vertical lifting system at the wellhead to achieve continuous slag removal during underground shield tunneling construction in a narrow wellhead construction site. This not only improves excavation efficiency but also reduces construction costs, solves construction problems, and provides reference for similar projects in the future.

Peculiarities of the alienation of the real estate object located on one’s own land plot

The article is devoted to the study of issues of legal regulation of relations related to the transfer of ownership of a plot of land in the event of acquisition of ownership of a real estate object located on it. It was established that the implementation of the principle of a single legal share of the land plot and the real estate object on it is carried out in accordance with the requirements of land and civil legislation. The need to determine the quality of priority land legal norms was noted. It was found that the legislative innovations contributed to the unification of the regulatory and legal regulation of the implementation and practical implementation of the automatic transfer of the right to a land plot when the right to a residential building, other building or structure on it is transferred. The mechanism of simultaneous transfer from the expropriator (previous owner) to the acquirer of the real estate object of ownership of the land plot on which such an object is located is analyzed. The grounds and conditions under which such a transition is possible have been clarified. In addition, the issue of legislative regulation of real estate objects, with the acquisition of ownership of which provides for the automatic transfer of ownership to the land plot on which they are located, is also disclosed. Approaches regarding the need to improve norms due to their uncertainty (contradiction) were supported. The special requirements for the contract providing for the transfer of ownership of the real estate object located on the land owned by the alienator were analyzed, the subject and essential terms of the contract were clarified, and the feasibility of improving the legal requirements on the specified issues was noted. Taking into account the analysis of the formed judicial practice, the relevant issues of the consideration of disputes related to the provision of the principle of a single legal destiny of the real estate object and the land plot on it were analyzed, the problems of independent construction, acquisition of ownership rights to it were considered. Attention is focused on the issues of further improvement of land legal norms in order to ensure the effective functioning of the procedure for transferring the right to a land plot in the event of acquiring the right to a real estate object located on it.

Mechanical and instability analysis of asphalt overlay during construction on cement concrete pavement with a large longitudinal slope

ABSTRACT There are insufficient stability problems in overlay construction on tourist highways in mountainous and island areas, especially the pavement with a large longitudinal slope. To elaborate on the instability characteristics of overlay, the construction stage of overlay is divided into loose state, paving stage and initial compaction stage. The moulding methods of specimens during the paving and initial compaction stages were determined. The evolution law of contact-slip characteristics and shear strength of overlay was analysed. The mechanical models of the construction stability of the composite pavements were constructed, instability characterisation methods were proposed and instability characteristics of asphalt overlay during construction were discussed. The results show that the paving state of overlay can be simulated by changing the rolling frequency and the compaction number. There is a risk of slip instability of loose overlay and the longitudinal gradient should be less than 12% to reduce this risk. The critical instability equivalent area ratio and critical slip area proposed can quantitatively describe the shape of the instability body and the instability critical condition. The longitudinal gradient significantly affects the interlaminar instability, but the internal instability mainly depends on the shear strength of asphalt overlay.

CREATION OF A NEW METHODOLOGY FOR THE DEVELOPMENT OF DESIGN COMPETENCE AMONG FUTURE ENGINEERS

This article explores the challenge of developing design competence in engineering students, a skill set increasingly vital in the face of modern technological demands. It introduces a novel methodology aimed at enhancing the training of future engineers, equipping them with the necessary tools to solve complex design and construction problems effectively. Grounded in an in-depth analysis of current engineering education practices, the proposed methodology integrates modern technologies, project-based learning, and an interdisciplinary approach to create a comprehensive and innovative educational framework.

RECOMMENDATIONS ON THE URBAN NETWORK FOTL STRUCTURE WITH THE LOWEST POSSIBLE LEVEL OF DISTORTION OF INFORMATION AND CONTROL ILCF-SIGNALS

The article studies the problem of construction of subscriber branched networks xPON/MAN/RoF, on the base of fiber-optic transmission lines, with the possibility of non-relational control. Namely, enabling transmission of control information as a part of subscriber signal. It is proposed to use instantaneous wavelength change function of the optical signal (ILCF)as the control information with parametric characteristics. A method of modeling such segments was offerred, nature of ILCF was analyzed, and recommendations on inclusion of EDFA light guides and methods of pumping to them from the point of view of maintaining positive chirp for the information-control ILCF signal were made. It was assumed that ensuring positive chirp will minimize distortion of the latter during its transmission. It is concluded that branching has significant effect on ILCF. Recommended parameters of segments for different degrees of their branching are also obtained as well.

“We Are Alone Here Like Orphans”: Leningrad Students’ Rural Practice in the Initial Period of Collectivisation

In this article, the author explores the problems of collective farm construction in the north-west of the RSFSR. The purpose of the article is to introduce into the academic circuit a set of ego-documents, reflecting household and economic peculiarities of everyday life of the Leningrad region peasantry during the period of continuous collectivisation. The study draws on the texts of two industrial practice diaries of Leningrad branch students of the Communist University of National Minorities of the West for December 1929 – January 1930, which are part of a set of similar documents identified in the Russian State Archive of Social and Political History, previously unknown to researchers and not reflected in the historiography. The texts are prepared for publication according to the accepted archeographic rules. The publication of the diaries’ contents is intended to familiarise the academic community with this type of historical sources and to show their information potential. Student diaries make it possible to expand the source base of research in the field of the history of everyday life in the Soviet rural areas and the Bolshevik cultural revolution. These documents can also be used in prosopographical studies on the lives of political workers and educators of the 1920s–1930s.

Intelligent System of Constructing Vector Diagrams of Electrical Circuits

Phasor diagrams are a powerful tool for visualizing and understanding the distribution of current, voltage, and power in electrical systems. During Russia's war against Ukraine, our energy industry has become very vulnerable to enemy attacks, and therefore needs a quick and effective recovery. Energy specialists lack software tools for working with the power system, and in the period of development of artificial intelligence, creating such tools is not so difficult. For example, familiar specialists often have to build vector diagrams - tools for visualizing and understanding the distribution of current, voltage and power in electrical systems. Using a combination of frameworks for working with artificial intelligence and creating a graphic shell, you can achieve the desired result in a few months, and at the same time do a useful thing for our victory. The YOLO model (based on the PyTorch framework) and the QT framework are considered among the proposed tools for creating an intelligent vector diagram construction system. The role of artificial intelligence is to recognize electrical elements in circuits and their connections to each other. Creating a user interface is an equally important thing, which is already implemented in many places with the help of QT. As of today, there is no specialized software tool for solving the problems of manual construction of vector diagrams, but the proposed approaches are already used for its creation. The system uses the Yolov5 model to recognize electrical elements on the circuit. The model is trained on more than 150 images and is able to recognize hand-drawn diagrams. Recognition is run as a separate process from the main program written in C++. This part of the system processes the input data from Yolo, saves it in a convenient format, creates a user interface, and displays the result as a vector diagram.

Long-Term Performance of Natural Stone Cobbles for Paving Raised Junctions: Findings from over a Decade of Use

Raised junctions (RJs) are chosen more and more frequently by town planners and road designers in traffic calming (TC) projects. This choice is supported by analyses of the existing transport systems in question. Where a few raised junctions have been designed for the project, use of different paving options may be worth consideration. This article describes a situation where a few RJs were placed on a short street section, all of which were provided with a cobblestone or cobblestone pavement (SBP). In order to verify the commercial viability of this option, we examined the traffic conditions, assessed the severity of condition of the pavements under analysis, and estimated the vehicle accelerations (ACs) and decelerations (DEs) in two chosen study areas, further referred to as the first and second study area. Two noise surveys were also carried out for the purposes of this research: the first one after a few years of operation and the second one after another ten years. Considering the problems of sustainable road construction, many environmental factors were taken into account in the studies. Based on the experimental results, we could assess the effectiveness of using RJs as the only TC measure in 30 km/h zones and check whether the severity of pavement condition depended on the AC and DE values and if SBP can be recommended to mitigate environmental impacts of street traffic. Finally, two pavement structures are proposed to choose from, depending on the local transport system conditions and streetscape characteristics. In addition, the authors recommend the use of solar-power elements at RJs to enhance their visibility and increase the traffic slowing effect.

Thermo-mechanical behaviour of newly developed fabric-reinforced engineered geopolymer mortar

Geopolymer technology is a spectacular technique which provides solutions to several construction problems in a sustainable way. In the primary stage of this research, geopolymer mortar using industrial and agro wastes, such as fly ash and sugarcane bagasse ash (SCBA) was developed. It was found that the geopolymer mortar with 10% SCBA shows good mechanical and durability properties. In the second stage of this research, engineered geopolymer mortar (EGM) using 10% SCBA content and polypropylene (PP) fiber was developed. In the final stage of this study, a novel strengthening system made of fabric-reinforced engineered geopolymer mortar (FREGM) composites was developed using EGM and glass fabric. To characterise mechanical response, the FREGM material has been subjected to flexural and tensile tests. It was discovered that 4-layers of glass fabrics attained 21.87 MPa flexural strength. The feasibility of practical applications of this newly developed FREGM material was checked by using it for strengthening the cylindrical and beam specimens. For the cylindrical specimen, the test variables include methods of installations (cast-in-place and prefabricated), number of glass fiber fabrics, and test temperature (200 °C, 400 °C and 600 °C). The cast-in-place cylinder specimen achieved 6% higher load carrying capacity than the precast cylinder, and 30% higher load carrying capacity than the control specimen. The beam specimens strengthened with geopolymer mortar, EGM and FREGM materials performance were evaluated by studying the load- deflection behaviour, cost analysis, ductility factor, crack and installation methods (cast-in-place and prefabricated). It is found that the cast-in-place beam specimen achieved 9.5% more strength than the precast beam and 46% higher than the control specimen.

Non-separable multidimensional multiresolution wavelets: A Douglas-Rachford approach

After re-casting the wavelet construction problem as a feasibility problem with constraints arising from the requirements of compact support, smoothness and orthogonality, the Douglas–Rachford algorithm is employed in the search for multi-dimensional, non-separable, compactly supported, smooth, orthogonal, multiresolution wavelets in the case of translations along the integer lattice and isotropic dyadic dilations. An algorithm for the numerical construction of such wavelets is described. By applying the algorithm, new one-dimensional wavelets are produced as well as genuinely non-separable two-dimensional wavelets.

Divergences based Bayesian inference with censored data

. In this work, we deal with some Bayesian inference problems in the presence of right censored data. First, we propose a dual ϕ−divergence Bayes type estimators for parametric models and we establish their asymptotic normality. To establish this result, we need a uniform strong law of large numbers that we prove as well. Then, we consider the problem of prior distributions construction for model selection using ϕ−divergences. Finally, we consider the problem of the predictive density estimation on the basis of ϕ−divergences. We apply an expansion result of the generalized Bayesian predictive density on two parametric models widely used in survival analysis, namely the Weibull and the inverse Weibull model, under right censoring. We also check the performances of our proposed methods through simulations and real data applications. The results of these studies show that our proposed dual ϕ−divergence Bayes type estimators are more robust than other Bayesian estimators. Moreover, the generalized Bayesian predictive density performs better than the classical estimative density especially for the inverse Weibull model.

STUDY LITERATUR : GRAPHENE, NANO TEKNOLOGI SEBAGAI MATERIAL KONSTRUKSI MASA DEPAN

The development of science and technology encourages progress in various fields, especially through academic innovation. In 2010, Andre K. Geim and Konstantin Novoselov won the Nobel for their discovery of graphene; using tape and graphite. Graphen, known as nanotechnology; superior, has conductive, strong and elastic properties, with these superior properties making graphen a material that has great potential for use in construction activities, such as steel wire ropes for bridges. NASA plans a lift to space using graphene; because of his strength. This research analyzes publications from various sources such as Google Scholar, Dimension, and Research Gate, exploring the attributes of graphene and its derivatives to improve the properties of composite cements and future construction. With the same basic properties as Graphene, Graphene oxide (GO) is also able to increase the compressive, tensile and ductility strength of concrete, reduce cracking, provide electrical conductivity, increase corrosion resistance, and improve the workability of the concrete mixture. Although its use in construction has great potential to overcome future construction problems. However, to be able to use graphene in construction activities, it still requires a lot of development and research.