bluuebunny/crossref_metadata_2025 huggingface dataset:
Active vibration suppression of a beam using piezoeffect
Authors: Rogacheva Nelly
Published: May 2019

Operation of structures and equipment in dynamic conditions led to the problems of vibration isolation and vibration suppression. For vibration isolation and vibration suppression passive, active systems and their combinations are used. Passive vibration isolation usually consists in the fact that the protected object relies on extremely dimensional springs and vibration isolators. Vibration isolation systems containing only passive elastic and damping elements are called passive. Active vibration isolation and vibration damping systems use external energy sources. These are pneumatic, hydropneumatic and hydromechanical devices. Recently, electro-elastic and magneto-elastic systems [1], [2] began to be used for vibration isolation and active vibration suppression. As a rule, the analysis of the work of such systems consists in the development of an experimental layout and a schematic diagram. In this paper, a mathematically based model is used to solve the problem in question. The calculations are performed and the results are presented in the form of graphs.
Methodical Approaches to the Development of Embankment Arrangement Projects
Authors: Danilchenko Vadim , Kasyanov Vitaliy
Published: May 2019

the main research question is the problem of methodological approaches to the development of embankment arrangement projects. Recently, in our country, great importance has been attached not only to the improvement or reconstruction of embankments, but also to comprehensively addressing many issues, such as the preservation of the historical heritage of our culture, ecology, safety, economy, multifunctionality, etc. The aim of the study is a systematic integrated approach to solving the tasks of arranging embankments, the proposed systems perform several functionals at once and allow to solve environmental, technical, aesthetic and economic problems. To solve the problem of arranging embankments, normative documents, domestic and foreign experience, innovative technologies, modern materials and advanced methods for improving embankments were studied.
Modeling the Influence of Weather and Climatic Conditions on the Safety Characteristics of the Construction Process
Authors: Evseev Vadim , Barkhi Reza , Pleshivtsev Aleksandr , Scrynnik Anton
Published: May 2019

This study investigates the influence of climatic conditions on the performance of the construction process and the characteristics of the elements of the construction process: construction machines, workers, the estimated cost of construction, and the reliability of construction deadlines. As an integral indicator of weather and climatic conditions, the indicator of “weather hardness” was chosen. The method of simulation modeling with its ability to generate random numbers with the given parameters is chosen as a mathematical model on a computer. The aim of the study is to identify the regression and correlation relationships between the indicators of weather hardness and the corresponding indicators of the elements of the construction process: the Fund for working time of workers, the coefficient of technical readiness of construction equipment, increasing the estimated cost of construction, increasing labor costs for the re-installation of construction equipment, identification of additional costs by types of work, for all the stated dependencies, regression equations are obtained. The results are presented in graphical form, and the results show that the proposed simulation model of the impact of weather and climatic conditions on the characteristics of the construction process allows to optimize management decisions, and reduce construction risks, reduce the estimated cost of construction.
Multifactorial parametric model for assessing and making organizational decisions to ensure the quality of construction
Authors: Zhuravlev Pavel , Bachus Evgeniy , Markova Irina
Published: May 2019

As noted by a number of experts in the field of the quality of construction of capital construction objects, at present there are no industry-specific methods for assessing the quality of construction and installation works in construction. The quality assessment and acceptance of capital construction objects is carried out according to the criterion of compliance with the requirements established in the project documentation, the working documentation prepared on its basis and the requirements established in the regulatory documents. It should be noted that the more complex the object, the larger the construction volume, the longer the construction period of the object and the harder it is to achieve full compliance of the object with the established requirements due to the lack of a methodology for choosing organizational decisions, as well as changing regulatory requirements, technological variability, errors.The current situation necessitated the development of an assessment model and the adoption of organizational decisions to ensure the quality of construction. This article highlights and discusses the main factors affecting the quality of organizational decisions. A system for assessing the level of quality assurance of construction is proposed, taking into account the quality of organizational decisions and the main factors cited.
Evolutionary optimization of reinforced concrete beams, taking into account design reliability, safety and risks during the emergency loss of supports
Authors: Tamrazyan Ashot , Alekseytsev Anatoliy
Published: May 2019

An algorithm has been developed to optimize the reinforced concrete beams in removing the supports based on an adapted genetic algorithm and RBDO approach. Multiple cross-sectional dimensions of elements, concrete class, class and diameter of the reinforcements vary. Avoiding significant changes in the geometry of the structure after emergency actions is considered as the main active constraints. It is believed that this constraints provides the required structural resistibility in an emergency situation. The value terms of material losses risk in case of a possible structure failure as a component of the objective function is considered. The proposed genetic algorithm includes an adapted mutation operator and the elitism strategy for selecting the best solutions. The algorithm presented allows obtaining design solutions of high operational reliability for rectangular reinforced concrete beams, taking into account the optimal ratio of a structure costs and the risks of its failure in an accident.
Experimental and calculated evaluation of carbon fiber reinforcing for increasing concrete columns carrying capacity
Authors: Kuzina Ekaterina , Rimshin Vladimir
Published: May 2019

The article presents the concrete columns tests results reinforced with canvases based on carbon fibers FibARM Tape 530/300 and FibARM Lamel 14/100 slats, the calculation of the use effectiveness for strengthening the compressed reinforced concrete elements. Three groups of columns were tested: unreinforced columns, columns reinforced with FibARM Tape 530/300 canvases in one layer, reinforced with FibARM Lamel 14/100 lamella (width is 100 mm), while one of the samples was reinforced with lamella only, and the other was reinforced both lamella and clamps. In addition, it was proposed calibration calculation of concrete columns reinforced with canvases based on carbon fibers FibARM Tape 530/300, the calculation purpose was to determine the bearing capacity for evaluating the suitability in the further structure operation after columns strengthening. According to the experiment results, data were obtained on the carrying capacity of centrally compressed concrete columns reinforced with carbon fiber both with a discrete arrangement of bands (strips) made of composite material along the height of the structures, as well as with their continuous wrapping (analogue of reinforced concrete holder). According to the experiment results, data were obtained on the carrying capacity of centrally compressed concrete columns reinforced with carbon fiber, both with a discrete arrangement of bands (strips) made of composite material along the height of structures, and with their continuous wrapping (analogue of reinforced concrete holder).
Modular frame trusses of buildings
Authors: Granev Viktor , Kelasiev Nikolay , Kodysh Emil , Trekin Nikolay , Terekhov Ivan
Published: May 2019

The paper describes space-planning and structural concept in source-efficient buildings that provides multiple functions of the rooms and large-span space.The main load-bearing structures of two adjacent storeys are metal trusses with parallel chords between which (between top and bottom chords) intermediate storeys are designed and the space between trusses is occupied by the free plan storeys. Bottom and top chords of the truss resist together with floor structure forming two-storey steel-reinforced concrete unit. To calculate value of deformation capacity for nodal connection a numerical experiment focused on modelling a part of building from solid finite elements has been performed. The results of performed analysis are the average values of stiffness of nodal interface of solid floor slab on corrugated deck and truss chords for finite elements KE 55 of typical layout (of flat finite elements). The obtained average values of stiffness were introduced into structural design of flat finite elements. Taking into account flexibility of floor slab that supported by middle trusses for the given structural concept leads to decreased span bending moments and increased support bending moments by 25% compared with hinge support of floor.
Forecast of deformations of the land surface from the separate clearing development, displacement and deformation in the main sections of the trough
Authors: Makeeva Tamara , Trofimov Vitaly
Published: May 2019

Two approaches for the description of parameters of the trough of the land surface subsidence in the main sections (its forms, inclinations and curvature) are considered in comparison with each other. One of them, (the method of standard curves) makes up the basis for “Rules of the structures protection...”, the document defining the approach to the assessment of deformation of the day surface during design of various facilities, located on it. Besides, the approach, developed in some other works by the authors, based on the approximation of the form of the trough subsidence with the functions of the probabilities integrals type with three defining parameters, is considered. The attempt to express the standard curves as the mention functions is undertaken. It is proved that it is possible to define the values of three corresponding parameters of the approximating functions. Thereby the tabular dependences are transformed to the analytical relations, correct for all the range of the parameters change, i.e. not just for those, recorded in the tables.
The results of numerical simulation of the work of the geotechnical screen of a sparse row of piles
Authors: Znamenskiy Vladimir , Morozov Evgenii
Published: May 2019

This article is devoted to a computational investigation of the work and the effectiveness of using a geotechnical screen from a sparse row of piles to reduce the yield of the building foundation of surrounding buildings caused by the installation of a reinforced concrete “diaphragm wall”, which serves as a barrier for a deep excavation, opened for the construction of a new building erected in constrained urban conditions. As a result of studies carried out using the MIDAS GTS NX software package, it was shown that the curtain grouting depends on the parameters of its design, which include the axial distance between piles, their diameter and length, and the location between the trench under the “diaphragm wall” “And the protected building, reduces the precipitation of buildings surrounding the buildings, caused by digging up the trench, by 50-60%. Analysis of the obtained data allowed us to establish the most significant parameters affecting the efficiency of geotechnical use on the screen of the rarefied number of stilts, define the limits of the maximum efficiency of its use and give practical recommendations for its design.
The effect of shear deformations on the stressed state of the wooden elements of the composite section on inclined metal rods
Authors: Linkov Vladimir
Published: May 2019

Wooden structures of composite cross-section can be made on flexible links in the form of inclined metal rods (NMS) without the use of glue. The compliance of joints is manifested in the shear deformations of the elements to be joined and reduces the carrying capacity of the composite wooden structures. The article discusses the effect of compliance of NMS-compounds in the form of inclined screwed rods on the stress-strain state of the wooden structures of the composite section. The results of tests for transverse bending of composite wooden elements of natural dimensions are presented. The effect of deformations of mutual shear of joints on deflections on normal stresses in the middle of the span of structures and stresses in inclined screwed rods is considered. It was established experimentally that a linear dependence of the form is observed between shear deformations and other parameters of the stress-strain state of structures Y = a*X + b, increase in shear deformation of NMS-compound on screwed rods on 1 mm leads to an increase in deflections, stresses in the construction of a composite section and in inclined rods on 8,39 mm, 0,24 MPa и на 20,8 MPa respectively.
Accuracy of pile capacity assessment on the basis of piling reports
Authors: Rainer Jakub
Published: May 2019

Current assessment of foundation pile bearing capacity during driving may considerably improve operational reliability in terms of loads to be transferred. It also enables proper design and trial examinations by focusing attention on piles with atypical driving characteristics. The paper presents the method applicable to assess the bearing capacity of prefabricated driven piles and provides analysis of likelihood of this assessment by the example of numerous prefabricated piles documented by piling reports and results of static pile load tests to the extent allowing to determining the limit bearing capacity. The results attained could be the basis to determine respective safety factors in pile design based on driving resistance analysis.
Experimental research of punching shear mechanism of reinforcing concrete slab
Authors: Trekin Nikolay , Pekin Dmitrii
Published: May 2019

The analysis of various regulatory methods for calculating reinforced concrete slabs for pushing and comparing with experiment results is made. The tested sample, measuring equipment and test bench are described. Sizes and materials for experimental prototype were chosen by existing beamless and capless slabs of monolithic reinforced concrete superstructures with column grid from 8×8 to 9×9 m.

Experimental research results of reinforcing concrete plate structure are presented for study purpose of stress-strain state when punching shear collapse occurring. Various aspects and observations obtained during the test are given. The comparison of the tested slab fragment with the complete response of slab structure is performed.

Analysis of tested sample stress-strain state and punching bearing capacity calculations results in according to existing regular standards were made. Main criterias of punching shear collapse were determined and new procedure for punching calculation of RC concrete slabs was offered basing on significantly new approach in punching bearing capacity defining.
Buckling of Compressed-Bent RC Elements of Frame-Bracing Structural System at “Unknown” Accidental Impacts
Authors: Fedorova Natalia , Savin Sergey , Kovalev Vladislav
Published: May 2019

The paper presents the results of studies of the buckling of the bearing elements of the new structural system, which consists of reinforced concrete precast-monolithic panels-frames produced industrially under a special accidental impact caused by a sudden column removal from the building frame. It is established that under special accidental impact caused by a sudden column removal from RC precast-monolithic structural system consists of industrial panel-frame elements, the reason of the fracture spreading within and outside local damage (fracture) zone may be the buckling of compressed-bent elements.
Cascade method of Stretched Elements strengthening by FRP
Authors: Danilov Aleksander , Kalugin Ivan
Published: May 2019

Subject - analysis of applicability and effectiveness of cascade type models in design of strengthening of stretch elements by gluing on their surface fiber reinforced polymers (FRP). Research objectives – cascade method of stretched elements reinforcement with adhesive joints presentation. Materials and methods – few variants of FRP-reinforcement with application of FEM simulation and analytic approach. A number of diagrams and tables represent the results. Results - a highly efficient and cost-effective method of strengthening the stretched elements to increase their bearing capacity reserves, the features of the bonded joint behavior, the equations and formulae for analysis and design. Conclusions - the name “cascade” reflects the features of the proposed strengthening design. The base element relaxation is gradual with each successive element attached. Analytical expressions in a rather general form are obtained and presented to design the cascade strengthening scheme. Design examples concentrate on the analysis of the adhesive joints application to attach FRP elements. The results suggest the effective use of adhesive joints to strengthen rather strong, including steel, stretched elements. The cascade method eliminates the indispensable use of highly expensive high-strength materials, thereby reducing the cost of reinforcement structures.
Study on safety and reliability of low-temperature tanks with perlite loose insulation during seismic events
Authors: Shigapov Rustam , Kovalchuk Oleg
Published: May 2019

A low-temperature tank is a type of tanks, that is used to store gas products in a liquid form at constantly low temperature under relatively low pressure. There are some features in the structure of this type of tanks. The main feature is the presence of thermal insulation. One of the most frequently used variants of low-temperature tanks is the type that consists of two cylindrical vessels with loose perlite insulation in an interwall space. Usually, it is concluded that the inner vessel and outer vessel act independently of each other during seismic events, but the rightness of this assumption is hardly ever investigated. This lack of study may cause serious safety issues, provoking underestimation of seismic loads on the inner and outer vessel as well as neglecting other complex effects such as influence on the form and frequencies of excited modes of the coupled flexible tank wall and fluid motion. In this paper principal effects of loose perlite insulation and its influence on seismic behaviour of two-vessel storages are discussed.
Influence of the stiffness coefficient of an elastic foundation on the frequency of free oscillations of polyethylene pipes in a semi-underground laying
Authors: Sokolov Vladimir , Razov Igor , Volinets Sviatoslav
Published: May 2019

The article is about the study of the frequencies of free oscillations of a large-diameter polyethylene gas pipeline with a semi-underground installation, which carried out on the basis of the solution for a semi-underground thin-walled steel pipeline of large diameter. As a result of oscillations, the cross section of the pipeline is deformed, but it strongly depends on the geometrical and mechanical parameters set, for example, on the stiffness coefficient of the elastic medium
Layered composite and contact layer. Effective modulus of elasticity
Authors: Andreev Vladimir , Tsybin Nikita , Turusov Robert
Published: May 2019

The effective modulus of elasticity of a layered composite is one of the important characteristics. At the moment, the so-called mixture formula is most often used to calculate this characteristic. However, as a number of experiments demonstrate, the formula of the mixture does not always allow calculating the effective modulus of elasticity. The reason for this fact is the inhomogeneous stress-strain state arising in a layered composite. This article presents a method for finding the effective modulus of elasticity of a layered composite based on the contact layer model. Such approach to the calculation allows us to take into account not only the volume content of the composite components, but also many other parameters of the model.
Stabilization of hydraulic characteristics for non-pressure pipelines
Authors: Orlov Vladimir , Zotkin Sergey
Published: May 2019

The article presents the aspects concerning the preservation of the transporting capacity of the waste water flow in the gravity pipeline during its trenchless renovation by polymer pipes. It is shown that the priority measure to preserve the required degree of self-cleaning of the restored pipeline section, as well as these ones adjacent to it, are the values of the water flow rate and filling in the pipe, which allows to provide the necessary transportation capacity of the entire pipeline system. A formula for determining the length of the rate destabilization zone is proposed and the calculation results using an automated program are given. The program algorithm includes the functions to determine the hydraulic friction coefficients of the pipeline material depending on various parameters, as well as the diameters and lengths of all sections. The essence of the calculations using an automated complex is described and the comparison of the calculation results under different conditions is made. There are given practical recommendations for the potential achievement of the hydraulic balance in the pipeline system and the creation of conditions under which the destabilization zone on the site after the repair becomes minimal.
Effect of parallel connection of pumping units on operating costs of pumping station
Authors: Ikramov Nazir , Kan Eduard , Mirzoev Mirasil , Majidov Takhir
Published: May 2019

In Uzbekistan, as well as in many other countries of the world, pumping units operate in parallel into a common pressure pipeline at some pumping stations of the irrigation system. This was done mainly to save on the capital costs of the pipeline. Analysis and hydraulic calculation of the existing large irrigation pumping stations with pumping units operating in parallel showed that at some of them the conditions of parallel operation of pumping units were impaired. As a result, a negative hydraulic process arises, in the form of self-induced vibrations of the water flow in the pipeline, which leads to various damage and deformation of the pressure pipeline and pipeline supports. The calculations showed that with different modes of pumping units operating together, the power consumption at the Amu-Bukhara-1 and Namangan pumping stations, accounting for one unit increases by 0.72 ... 6.53%, and at the Amu-Bukhara-2 and Amu-Zang-2 pumping stations, this index, on the contrary, decreases by 0.32 ... 1.67%. Therefore, a properly selected operating mode of parallel-connected pumping units will lead to a decrease in operating costs, i.e. decrease in the prime cost of raised water.
Full-scale testing of water intake pumps of pumping stations
Authors: Bakhriddin Khasanov , Azam Azimov , Alisher Djurabekov
Published: May 2019

This article is devoted to methods analysis and systems for maintaining the forebay operating modes of pumping stations, which the minimum cost of resources is provided. In modern conditions there is a need to implement measures and solutions to improve the operational performance of pumping stations, which would lead to a decrease in the cost of water supplied. Such activities include the development of methods and systems for the management and maintenance of stations operating modes, which provide the minimum cost of resources. Based on observations, the uneven operation of pumping units over time and as a result of imperfect design of advance cells, the design hydraulic indicators of flow and operational parameters of pumping stations deteriorate. The relevance hydraulic research of forebay regimes and water intakes indicated at a number of meetings on pumps quality. With the development of the recommended set of measures, it is possible to save water and energy resources. The purpose of the work was to conduct full-scale testing of forebay on a large pumping stations in operation, to develop a new design of forebay and its hydraulic calculation. During work performing, energy-hydraulic methods for determining the parameters of pumping units were used.
Numerical Modeling of pipes conveying gas-liquid two-phase flow
Authors: Khudayarov Bakhtiyar , Komilova Kholidakhon , Turaev Fozilzhon
Published: May 2019

Results of studies of the oscillations of pipelines conveying a two-phase slug flow are presented in the paper. A viscoelastic model of the theory of beams and the Winkler base model are used in the study of pipeline oscillations with a gas-containing slug flowing inside. The Boltzmann-Volterra hereditary theory of the viscoelasticity is used to describe the viscoelastic properties of the pipeline material and earth bases. The effect of gas and liquid phases flow rates, influence of tensile forces in the longitudinal direction of the pipeline, parameters of Winkler bases, parameters of singularity in the heredity kernels and geometric parameters of the pipeline on the oscillations of structures with viscoelastic properties are numerically studied. It is revealed that an increase in the length of the gas bubble zone leads to a decrease in the amplitude and oscillation frequency of the pipeline. The critical rates for a two-phase slug flow are determined. It is revealed that an increase in the soil density of the bases leads to an increase in the critical rate of gas flow. It is shown that an account of viscoelastic properties of structure material and earth bases leads to a decrease in the critical flow rate.
Experience of employment of computational models for water quality modelling
Authors: Krutov Anatoly , Bazarov Dilshod , Norkulov Begzod , Obidov Bakhtiyar , Nazarov Bobur
Published: May 2019

The purpose of the article is to develop the required and sufficient conditions under which numerical methods can be used for engineering calculations and for scientific research of hydrodynamic processes in solving practical problems related to predicting the spread of pollutants in water bodies and streams. The conducted studies consisted in comparing the results of laboratory experiments and mathematical modelling, in particular the distribution of heat in a stream with different temperature in water layers was studied. To check the adequacy of the proposed numerical models, calculations were performed and comparisons were made with the results of experimental data. The obtained results allowed to determine the boundaries of the qualitative difference in the flow behaviour for different numbers of Froude and Reynolds. The accuracy of the method was also studied. A number of additional requirements for numerical models were proposed in addition to approcsimation and stability, such as requirements of conservativeness (divergence), existence of trivial solutions on grids, possibility to calculate highly unsteady, quasi-stable, pulsating and stationary flows, requirement of invariance of linearized equations, as well as the requirement of a one-dimensional scheme to be a consequence of a two-dimensional scheme. Distribution of velocities of wind currents using a three-dimensional and two-dimensional model was studied for a real object. A shallow-water bay of the Aral Sea was chosen as the object for the research. Comparison of the calculation results for both models showed that the flow velocity fields, as well as the distribution of pollutants in shallow waters, can be performed using a two-dimensional model.
The hydraulic resistance coefficient in the conditions of simultaneous effect of Re, Fr and Unknown node mfrac found in MathML fragment.$ {B \over h} $
Authors: Volgin George
Published: May 2019

One of the most important tasks of engineering hydraulics is to determine the energy loss during the motion of the fluid flow. The study of the question of whether the patterns of hydraulic resistances are similar in a calm and turbulent flow is relevant in the design of hydraulic structures. In most cases, a turbulent regime of fluid motion is observed in various applications, but to date, the theory of turbulence is not considered complete. When designing hydraulic structures, inaccuracies in the existing calculation methods can lead to a decrease in the efficiency and reliability of the entire spillway structure as a whole. The need for an integrated approach to the analysis of the impact on the hydraulic resistance of various factors is noted (degree of spread $ \left( {{B \over h}} \right) $), the degree of turbulence (Re) and the degree of flow roughness (Fr)), which is not always provided by known dependencies and methods of calculation. On the basis of our own experimental data, a new formula for calculating the hydraulic resistance of turbulent flows in smooth channels was obtained. The functional dependence of the hydraulic resistance coefficient on the parameters $ \left( {{B \over h}} \right) $, Re and Fr is obtained.
Filtration process in earth fill dam body and its chemical effect on piezometers
Authors: Yangiev Asror , Gapparov Furqat , Adjimuratov Dilmurod
Published: May 2019

Estimation of aggressiveness of filtration flow in the dam body is gaining importance in providing the stability of reservoir dam and its parts. In order to estimate the aggressiveness of filtration flow in the dam body it is necessary to know the movement pattern of filtration water in reservoir dam and its effect on dam elements. The article brings up the definition of gradients of filtration flow in the dam body, analysis of the reasons of their change by cross section at the example of Tashkent reservoir dam. Besides, chemical composition of water in piezometers has been analyzed, aggressive effect of sulfate salts on piezometers, and their corrosion have been determined. Measures on systematic piezometer observations are mentioned.
Technologies and Technical Means for Anti-Erosion Differentiated Soil Treatment System
Authors: Mirzaev Bakhadir , Mamatov Farmon , Avazov Ikromjon , Mardonov Sherzod
Published: May 2019

This paper highlights the necessity of system modification of the main soil slopes processing by developing new technologies of processing eroded soils and technical means to protect a soil from wind and water erosion, reduce processing energy costs, improve moisture accumulation and preservation, and increase the aggregate productivity. An improved differentiated system of slopes soil tilling is proposed, including a crest-stepped ploughing with complete alternation (at 180° within the range of own furrow) and incomplete turnover of the layers and mouldboardless two-tier tilling. During the first year, a crest-stepped ploughing was carried out on slope fields affected by water and wind erosion. Thus, stratum’s subsurface layers are strip loosened. To implement this technology, an improved plough for crest-stepped ploughing developed on the basis of a stepped plough for furrowless smooth tillage is proposed. The rotation was carried out with mould boardless two-tier soil tilling by a ripper with inclined posts. Further, it is recommended to develop and implement combined machines able to simultaneously conduct mould boardless and mouldboard soil tilling, strip subsurface loosening, fertilizer application and other manipulations to prepare soil for sowing and the sowing per one passage of the unit to protect soil from wind and water erosion.
Problems of water lifting machine systems control in the republic of Uzbekistan with new innovation technology
Authors: Ergashev Rustam , Artikbekova Fotima , Jumabayeva Gulnora , Uljayev Farouddin
Published: May 2019

The article presents the results of the study of the main categories of losses for the elements of irrigation systems, shows the experience of using pumping equipment on irrigation systems, discussed methods for increasing the volumetric efficiency, improving the hydraulic conditions for supplying flow to the impeller and reducing cavitation. The purpose of the research is the scientific substantiation of the usage of samples of modern pumps, in modern water-lifting systems in the context of import substitution programs with innovation technology. The results of the study of the main categories by irrigation system elements are presented, the experience of pumping equipment use on irrigation systems is described, the methods for increasing the volumetric efficiency, for improving the hydraulic conditions for supplying the flow to the impeller and reducing the cavitation wear are examined in the article. The complex solution of such problems as the increasing the efficiency of the pumping equipment was proposed, which allowed to increase the actual performance factor of the given pump from 83 to 88 %, compared to the factory data.
Development of the computerized decision-making support system for the prevention and revealing of dangerous zones of flooding
Authors: Shaazizov Farrukh , Uralov Bakhtiyar , Shukurov Elyor , Nasrulin Aydar
Published: May 2019

In considered article the results are presented of the carried out researches on high-mountainous lakes of the Tashkent area. Visual inspection of a modern condition of natural dams of considered high-mountainous lakes of the Tashkent oblast is carried out. On the basis of the analysis of visual inspection it is possible to note, that the common technical condition of natural dams of the submitted high-mountainous lakes safe and does not represent danger to downstream situated territories. It was carried out the modeling of occurrence of emergency situation on high-mountainous lakes of the Tashkent oblast in case of full or partial destruction of natural dams. By an available calculation method of flooding waves are determined its key parameters, height of a wave, speed of distribution of a wave of break on the certain distances and reaching time the given wave up to the certain distances. On the basis of calculation method have been calculated and put on cross-sections of the rivers Pskem and Kocy zones of possible flooding in full and partial destruction of dams of high-mountainous lakes. Results of the carried out calculations have been put on the digital map, created on platform ArcView 3.2a.
A Review of Evaporation Reduction Methods from Water Surfaces
Authors: Waheeb Youssef Yara , Khodzinskaya Anna
Published: May 2019

Many methods have been tested and developed all over the world to save water from evaporation process. This paper presents a state-of-art review of published research work in the last 14 years (from 2014 to 2018) in which it was focused on the physical, chemical and biological methods of evaporation reduction from water surfaces. The main characteristics, as well as the advantages and disadvantages of each method are indicated. Among these used techniques for reducing evaporation are physical methods that use floating or suspended covers and can save a large percentage of water (between 70 and 95%). The use of thermal mixing by compressed air seems to be very important for evaporation suppression on deep reservoirs (greater than +18 m). Moreover, currently chemicals are widely used to reduce water evaporation, such as WaterSavr, and can save relatively a small percentage of water (between 20 - 40%). Biological methods such as floating plants, wind breakers and palm fronds can provide a significant decrease in the volume of evaporation but they have some restrictions on their uses.
Modeling Procedure of Coastal Protection Shaped Blocks with High Wave Suppressing and Interlocking Capacity
Authors: Iordanishvili Irina , Iremashvili Inga , Ujma Adam , Shurgaya Vladimer , Kandelaki Nodar , Iordanishvili Konstantin
Published: May 2019

A groyne is a shore protection structure built perpendicular to the shoreline of the coast (or river), over the beach and into the shoreface (the area between the nearshore region and the inner continental shelf), to reduce longshore drift and trap sediments. A groyne field or system is a series of groynes acting together to protect a beach. Concret is often used as construction material.

On the basis of analysis of wave suppression efficiency and stability on the slope of more than one hundred existing shaped massives the new type of coast protecting reinforced concrete blocks – so called “Hexablock” (“Hexablock” was called because of its 6 facets) characterized with higher wave suppression properties, interlocking capacity, stability on the slope and longer life time is proposed.
Flow kinematics with oppositely rotating coaxial layers
Authors: Orekhov Genrikh
Published: May 2019

In modern technological processes, liquid and gas flows play an important role. This is especially mostly evident in hydraulic engineering and hydropower construction when designing the highly efficient hydraulic turbines, various spillway systems and other elements of layout patterns of structures. When designing and constructing such facilities, it is necessary to know the characteristics of the flows to be passed through these structures in order to correctly take into account the various types of impacts from the flow: pressure pulsations, cavitation and erosion due to cavitation, wave formation and abrasive wear. When designing high-head spillway structures, special attention is paid to the presence of excess energy from the stream entering the lower pool, which requires special measures to dissipate it. Nowadays, in the practice of construction of hydraulic structures, swirled flows are used including those with oppositely rotating layers. This type of flow creates a number of effects that allow one to radically solve the problems of energy dissipation of high-velocity flows. The report presents the results of studies of a complicated flow formed by oppositely rotating coaxially arranged layers of liquid made by a physical method. The description of the experimental stand for the model studies of such flows is given. The basic parameters of the installation, the principle of operation of the recording equipment and its main characteristics are given. The results of model studies in the form of distribution of the components of the flow velocity along the cross section of the flow conductor and its length are given.
Production of extra-strong concrete axisymmetric products
Authors: Khasanov Bakhridin , Mirzaev Temur
Published: May 2019

The article presents the results of many years of comprehensive research on the new technology of forming extra-strong unreinforced pipes for hydro-engineering construction by vibro-peristaltic hyper-compacting with simultaneous modifying of the concrete mixtures and concrete itself. The regularities of occurrence of a compacted mixture in a column of high-intensity compression and tension zones varying in time, as well as the placement and configuration of the filtration fields of the formwork forms, taking into account the type and diameter of the holes preventing their blockage in the molding process, are given. As a result of experimental theoretical and industrial research, the scientific basis for the production of highly durable concrete has been developed. Technological bases of its production in axisymmetric products, as well as a new installation for molding concrete unreinforced pipes by vibro-peristaltic pressing, which is protected by copyright certificate and patent of the Republic of Uzbekistan. The installation is intended for forming low-pressure and free-flow pipes with a nominal diameter from 500 to 1500 mm and a length of up to 2000 mm. The purpose of this article is to share the results of research, experience to accelerate the widespread introduction of new technology.
Methodological principles of the organization of reengineering in construction (capital construction facility reengineering and technological process reengineering)
Authors: Maslova Lyubov , Sborshchikov Sergey , Kochenkova Elizaveta
Published: May 2019

As practice shows, in conditions of crisis organizational problems and development issues, when accumulated contradictions lead to the competitiveness decline and loss of consumers, it is proposed an application of methods of reengineering, implementing turning around enterprises, organizations, companies through moving to a new quality level and modernization of the previously implemented engineering solutions of the functioning facility. The goal of the work is to find organizational forms of quality transformation of the solutions, having an anthropotechnical genesis (technical, technological, organizational, managerial etc.) through capital construction facility reengineering and technological process reengineering solutions. Literature sources and current construction standards analysis is carried out to implement the goal. Methods of the system analysis and management, comparison, expert evaluation are used. General definitions of the reengineering from Russian and foreign sources are given in the article. Criteria and factors of the reengineering events classification at the «construction facility – construction site» level are justified, the project of capital construction facility and technological process reengineering is set out, the capital construction facility reengineering structure is described, pattern solutions of the capital construction facility reengineering are formed, distribution of the reengineering types according to the stages of the life circle of the capital construction facility is presented. The structure of the capital construction facility reengineering standards is given and perspective directions of the information and analytical support development are indicated in the article. In the conclusion the fact, that reengineering is an effective mechanism of forming a comfort living environment, is justified based on the science and technology achievements, customer inquiry and most complete satisfaction, as well as the creation of the competitive edge of not only separate domestic construction organizations, but also the whole national construction field.
Optimization of construction parameters using resource scheduling
Authors: Kuzhin Marat , Akimockina Marina
Published: May 2019

Reducing the time of production within maintaining the cost of the final product is the main issue in construction organization. This question can be resolved through the development of network and calendar schedules with the correct sequence of work, composition of brigades, optimal technological decisions. The successful correction of schedules is possible by calculating parameters of resource graphics and comparing them with the normal indicators. The effectiveness of the applied methods of optimization by the time and resources depends on technological and organizational parameters of the designed building or construction.
Organizational-technological modeling of a multi-apartment residential house where overhaul is planned
Authors: Fatullaev Rustam
Published: May 2019

Using the potential of carrying out unscheduled repairs as a tool for evaluating the effectiveness of organizational and technological solutions is most effective when planning the overhaul of apartment buildings. In order that the potential obtained as a result of calculations could give the most objective assessment of organizational and technological solutions when carrying out unscheduled repairs, it is necessary to form an organizational and technological model of the object. This model gives a quantitative assessment of the influence degree of the constraint parameters and allows selecting the most effective organizational and technological model for the repair and construction works.
Selective separation of copper from copper-smelting waste acid by potential control
Authors: Yang Tianzu , Hu Bin , Liu Weifeng , Zhang Duchao , Chen Lin
Published: May 2019

An oxidation-sulfidation process by potential control was proposed for the separation of the Cu from copper-smelting waste acid (CSWA). This process consists of two steps: the oxidation of As (III) and the sulfidation of Cu by potential control. For the oxidation step, the oxidation efficiency of As (III) reached 99.4% under the following optimal conditions: a potential of 820 mV, temperature of 25 °C, and reaction time of 10 min. Subsequently, Na2S solution was pumped to the oxidized-CSWA and 99.4% of the Cu and 1.8% of the As were precipitated under the following optimal conditions: a potential of 508 mV, temperature of 25 °C, initial pH of 1.0, and reaction time of 30 min. It is confirmed that, the oxidation of As is the pre-requisite step for the selective separation of the Cu from CSWA via the sulfidation process. Therefore, the novel process realized a selective separation of the Cu, as well as provided an alternative option for the treatment of non-ferrous smelting waste acid.
Security of e-banking systems: modelling the process of counteracting e-banking fraud
Authors: Syniavska Olga , Dekhtyar Nadiya , Deyneka Olga , Zhukova Tetiana , Syniavska Olena
Published: May 2019

The paper is devoted to the current issue of the counteracting cyberattacks in the banking sector, in particular in the field of e-banking. The main types of banking fraud, which are carried out in the online sphere, are considered. The authors propose a mathematical model that describes the process of counteracting e-banking fraud. Proposed model is based on the classic Lotka-Volterra model with logistic growth and the Holling-Tanner dynamic models. The fixed points of a dynamic system were calculated and analyzed. It was determined that there are 4 possible types of fixed points: saddle and the line of stable fixed points, which are unlikely may be in real life, stable node and a stable degenerate node, which are, in practice, the most likely cases. The constructed model could be used for theoretical study, different simulation experiments with changing input parameters could be done. Unfortunately, it is difficult to investigate this question on real data, since the statistics on cyberattacks are closed.
Neural network and index forecasting of the strategies of development of the armed forces of Ukraine depending on their own economic opportunities and encroachments of the states of aggressors
Authors: Porokhnya Vasyl , Ostapenko Oleksandr
Published: May 2019

Ukraine has a relative drawback in the economic defense capabilities, which needs to be addressed by raising the indicators of macroeconomic development, innovation, and economic potential, social health of the population of the state, and the support of the Armed Forces of Ukraine, by the state. The estimation of the defense capability of states like Ukraine, Poland, Russia and Turkey is made on the basis of the developed methodological approach to the overall representation of the health of the economies of the states and their defense capabilities using the method of constructing petal diagrams with the definition of their effective areas, which became indicators of economic status and defense capability. The article analyses the dependence of the development level of the countries’ economies and the state of development of the armed forces of these countries in the conditions of resource constraints and existing risks on the basis of macroeconomic data and indicators. This article uses the indicators for the determination of the level of defense capability and the data of petal diagrams and the scenario modeling of the development strategies of the Armed Forces of Ukraine with the aim of constructing the most optimal forecast in this area.