bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrotransport of river sediments in hydroelelators
Authors: Arifjanov Aybek , Rakhimov Kudrat , Abduraimova Dilbar , Babaev Askar , Melikuziyev Sarvar 
Published: July 2020

Abstract
The article considers the hydrotransport of river sediment in a cylindrical pipeline. To describe the nature of hydraulic phenomena, experiments were carried out for single-phase and two-phase flows. Based on the results of the experiments, the main hydraulic parameters of the suction pipeline of the hydraulic elevator were determined during hydrotransport of river sediment. Based on the processing of available data, as well as data from specially designed experiments, the dependences of the flow coefficient at the expiration of the slurry flow from the hydraulic elevator pipeline on the Reynolds number are valid, which are valid for certain limits of the change in Reynolds numbers. The design parameters of the hydraulic elevator are substantiated, calculation formulas are given for determining the characteristics of a hydraulic mixture consisting of a solid particle and a carrier fluid. The methodology for calculating the concentration distribution and the method for determining the bottom concentration are given. A calculation formula is proposed for determining the flow rate and flow rate of a hydraulic elevator slurry. As a result of the analysis of these experiments, the dependences of the concentration of solid particles on the relative pressure in the hydraulic elevator are established.
Dynamics of an earth dam with account for rheological properties of soil under dynamic effect
Authors: Yangiev Asror , Salyamova Klara , Turdikulov Khusanboy , Fayziev Xomitxon 
Published: July 2020

Abstract
The design, construction and operation of high earth dams in seismic regions of the republic require continuous improvement of the methods to calculate them on basic loads and special combinations of them, including seismic ones. The aim of this work is to improve the calculation methods for earth dams, taking into account the real physical and mechanical characteristics of structure and its foundation soil under various types of loads. Improved calculation methods make it possible to predict the stress-strain state of the most vulnerable points in the dam, which will lead to a reliable and safe operation of earth dams in seismic zones.
Distribution of turbidity in flow constrained by transverse dam
Authors: Bakiev Masharif , Yakubov Kuvonch , Choriev Jamshid 
Published: July 2020

Abstract
Construction of control structures in rivers allows to manage channel flow in required direction and artificially change its natural condition providing rational interaction of flow and channel. Redistribution of both liquid and solid flow occur under influence of control structures. The main goal of the given work is to set the distribution pattern of turbidity in flow constrained by transverse blind dam. For the first time the task is studied with the use of field research data from dam No.30 in Amudarya river. The location of section and verticals in choosing turbidity samples, the sections are set based on the hydraulic structure of deformed flow. Flow division scheme has been proposed for hydraulically homogeneous zones of weakly disturbed core, intensive turbulent mixing and backflow, as it is accepted in the theory of turbulent flow with mixture spreading in a confined space. For the verticals the samples were taken in two depth points 0.2H and 0.8H, and areas with shallow depth – at 0.6H. Turbidity distribution by depth in weakly disturbed core has the shape of a “boot” and μ 0,8H is 2-3 times higher than μ0,2H . The rest are close to logarithmic. The maximal turbidity at 0.8H is 3.6 kg/m3. Turbidity distribution in layout in the zone of intensive turbulent mixing is affine and comply with Shlihting-Abramovih’s theoretical relationship for starting point. The obtained results can be used in future to forecast interdam area sedimentation and new bank line borders.
The height of a damless water intake structure threshold
Authors: Ikramov Nazir , Majidov Takhir , Kan Eduard , Ikromov Ilhomjon 
Published: July 2020

Abstract
More than 80% of the annual water consumption in Uzbekistan comes from large transboundary rivers such as the Amu Darya and Syr Darya. The rest of the water is formed on the territory of the Republic. Almost all year round, the turbidity of the Amu Darya and Zaravshan rivers is 3÷5 g/l, reaching 15÷18 g/l during flood periods.in most cases, water from the rivers is taken into irrigation channels using damless water intake structures. In order to prevent the ingress of bottom sediments from rivers into channels, thresholds have been constructed at water intake structures, the height of which is set constructively. As a result, bottom sediments pass through thresholds and move along the bottom of channels, reducing their cross-sections, as well as filling the chambers of pumping stations and pressure basins of hydroelectric power plants with sediments. After getting into the flow parts of pipelines and hydraulic machines (pumps and hydraulic turbines), they lead to abrasive wear, as well as other negative consequences. A lot of work has been done to prevent sediment from entering through water intake structures, but so far none of these proposals has provided an effective solution. In the laboratory of the Tashkent Institute of irrigation and agricultural mechanization engineers, a series of experiments were conducted on a glass hydraulic tray to determine the height of bottom sediments, taking into account their heterogeneity. Based on experiments, the dependence on determining the height of the ridge is derived. Based on the obtained dependence, a method for determining the height of the threshold of a damless water intake structure is proposed. This technique was experimentally tested on a laboratory tray. Specifying the threshold height will lead to optimization of capital costs for the construction of the threshold of the water intake structure, as well as reduction of operating costs for cleaning channels from sediment and repair work of hydraulic machines from hydroabrasive wear.
Effectiveness of energy-saving glazing in various climatic zones of Russia
Authors: Korkina Elena , Shmarov Igor , Tyulenev Matvey 
Published: July 2020

Abstract
Transmission heat losses through the filling of the apertures are greatest through the entire envelope of the building, therefore, their reduction is of great importance for saving energy for heating. For this purpose, the installation of double-glazed windows with special energy-saving coatings is being carried out. The purpose of this work is to estimate the decrease in heat losses while reducing heat gains when replacing glass packs with energy-saving ones for the whole building. For this purpose, an indicator was introduced that is equal to the ratio of heat loss reduction, taking into account the decrease in heat gains when replacing glass packs with energy-saving ones. This indicator was calculated using the example of a building, presumably located in different climatic zones of Russia. This indicator can be used in economic calculations when evaluating the effectiveness of energy-saving glazing.
Dynamic problems of scientific support construction
Authors: Ter-Martirosyan Armen , Sobolev Evgeny 
Published: July 2020

Abstract
This article presents the results of scientific support of the project and construction, as well as geotechnical monitoring of the multi-storey residential complex Bogorodsky with four towers of 35 floors and a developed underground part of two floors in difficult geotechnical conditions. In the immediate vicinity of the building under construction there is a line of high-speed city tram. In addition, since the building has a status of increased complexity, it is necessary to take into account the seismic load. As part of the geotechnical tasks of scientific support, in addition to assessing the displacement of the designed building and assessing the impact on the surrounding buildings, the forecast of additional displacements of the base from the effects of ground rail transport and seismic was considered. The geotechnical forecast was carried out by the finite element method in specialized software. The calculations are based on flat sections taking into account the elastic-plastic properties of soils. In conclusion, the results of observations of the displacements of the building under construction and the surrounding buildings are presented. Displacement graphs of geodetic marks installed on the structures of the building and surrounding buildings are presented. A comparative analysis of the results of the geotechnical forecast and the actual situation at the construction site.
Soil and structure interaction investigation features
Authors: Sidorov Vitalii , Almakaeva Anastasya 
Published: July 2020

Abstract
The interaction of soils with underground structures is an important and complicated geotechnical problem, because a new stress-strain state is formed on their contact, associated with reduced strength properties of soils. To determine these characteristics, laboratory tests by direct shear scheme with stiff clay and loam interacting with a concrete surface were carried out. Soil samples were taken from a depth of more than 35 m in Moscow. The tests were carried out according to the “soil-soil” and “soil-solid surface” schemes with a speed of 0.005 mm/min for clay and 0.05 mm/min for loam. According to the results of laboratory tests, strains and deformations were obtained. Also, the strength reduction factors were determined equal to 0.53 for clay and concrete and 0.44 for loam and concrete. This coefficient is one of the main parameters characterizing the magnitude of decrease of the strength characteristics at the contact in numerical calculations. Moreover, two methods for modeling the contact zone of the soil massif and a single pile were considered in the PLAXIS 2D software package. In the first case, the problem was modeled with use special contact elements “interfaces”, which have zero (virtual) thickness, and in the second case, the contact zone was defined by a layer of soil of real thickness, for which the properties are equivalent to the properties of the virtual interface. The results of numerical modeling showed that the shear stresses on the contact in the case of a real interface will be less than when using a virtual interface, and the bearing capacity of the pile will decrease by almost 2 times.
The effects of morphometric elements of the channel on hydraulic resistance of machine channels of pumping stations
Authors: Bazarov Dilshod , Uralov Bakhtiyar , Matyakubov Bakhtiyar , Vokhidov Oybek , Uljaev Farokhiddin , Akhmadi Makhfuz 
Published: July 2020

Abstract
Presents the results of hydraulic studies in pressureless and pressure water conduits, the results of which showed that the dependences obtained for calculating the hydraulic resistance in round pressure pipes cannot be distributed without the corresponding adjustments of pressureless channels (provided that the diameter of the pipe is replaced in the corresponding calculations with a value where hydraulic radius). In particular, it follows (and this is confirmed by the data of the corresponding experimental studies published in the literature) that in the case of pressureless channels, the pressure loss coefficient, and therefore the pressure loss, depends not only on the relative roughness and Reynolds number, but also on the shape of the cross section the channel. Moreover, if for hydraulically smooth pressureless channels this dependence can be considered to a first approximation clarified, then for channels whose wetted surface is characterized by the presence of a certain roughness, the question of its influence, as well as the shape of the channel cross section on the pressure loss, is far from roughly approximate solution. The paper also considers the general equation of fluid motion in pressureless channels and the functional dependences of the coefficient of hydraulic friction on the Reynolds number, relative roughness, and on the shape of the living section of the channel; resistance formulas are first for the simplest with respect to the cross-sectional shape of the channels (round and infinitely wide rectangular), and then for channels with a more complex cross-sectional shape. To take into account the effect (on the pressure loss) of the channel cross-sectional shape and the presence of a flow with a free surface in it, additional correction factors are introduced (using the hydraulic radius concept) as well as new dependencies and formulas for determining the hydraulic friction coefficient are given, s taking into account the influence of morphometric elements of the channel on the hydraulic resistance of the machine channels of pumping stations.
Kinematic characteristics of the flow, in the compression region, with bilateral symmetric restriction by floodplain dams
Authors: Bakiev Masharif , Kaxxarov Uktam , Jakhonov Azizjon , Matkarimov Otanazar 
Published: July 2020

Abstract
Of great importance is the solution of the problem of research aimed at improving design methods and calculating the parameters of a bilaterally symmetrically constrained river flow with wide floodplains, for regulating river channels, protecting river banks from erosion and for the efficient use of floodplain fertile lands.The aim of this work is to develop a methodology for calculating the flow velocity field in the compression region, which is bilaterally constrained by floodplain transverse dams. Experimental studies were carried out in a schematizaron channel with a bilateral floodplain of rectangular cross section with parallel dynamic axes. It was experimentally established that the velocity distribution in the zone of interaction between channel and floodplain flows obeys the universal Schlichting-Abramovich dependence. The relative width of the interaction zone depends on the ratio of the depths of the channel and floodplain flows. The device of transverse floodplain dams to conduct to the appearance of areas of backwater, compression and spreading. In the compression region, the greatest longitudinal and transverse differences in depths are observed, as well as the velocity field with zones characteristic of jet flows: a weakly perturbed core, turbulent mixing, and reverse currents. The problem is realized for the compression domain by a joint solution of the equations of conservation of momentum and conservation of flow in the stream. Design dependencies are proposed to determine the patterns of change in speed in the channel and on floodplains. In contrast to existing solutions, the interaction of channel and floodplain flows, uneven velocity distribution in the zone of a weakly perturbed core, and transverse and longitudinal differences in depth in the compression region are taken into account. The combined use of experimental and theoretical solutions allowed the establishment of kinematic flow parameters in the compression region of the flow constrained by floodplain dams.
To assessment of stress-strain state in rock continua
Authors: Adilov Farkhadjan , Makhmudova Shakhnoza , Abirov Rustam , Toshmatov Elyor , Maxmudova Ikbal 
Published: July 2020

Abstract
The approach for calculation of stress-strain state of mine excavation in rock continua is described in this issue. Boundary element techniques are used here. Proposed method can take into account existing cracks in continua and its propagation under dynamic or static loading.
Equations of motion of mechanical systems with nonlinear nonholonomic servoconstraints
Authors: Khusanov Kahramanjon 
Published: July 2020

Abstract
The proposed paper is devoted to the derivation of equation of motion for the systems with nonholonomic servoconstraints, taking into account the release from servoconstraints containing only tangential components of reaction force of servoconstraints taken as control parameters. Chaplygin’s problems and a gyroscope in gimbal mount are considered.
Automation of vibration modes of soil compaction machines
Authors: Drozdov Anatoliy 
Published: July 2020

Abstract
The relevance of high-quality compaction of soil foundations during the construction of embankments and foundations during the construction of engineering structures is given. An effective vibrodynamic method of compaction of gravel and sand materials for foundations of building structures for various purposes is substantiated and proposed. The method of continuous monitoring of the degree of compaction of the soil by measuring the magnitudes of the amplitudes and frequencies of harmonic oscillations of the compacted surface is determined. A schematic diagram of the automatic control system CAP of vibration modes of shock-absorbing soil compacting machines with a crank-oscillating exciter is proposed. The principle of regulating the operating modes of a vibrating machine using an automatic control pulse distributor is stated. A structural block diagram of the CAP elements is constructed and an analysis of the dynamic properties that determine the optimal control time is carried out. The main elements of the CAP are determined and their work in the control program is shown: the frequency of impact of the working mechanism on the soil surface being compacted, depending on the degree of compaction. Key words: soil compaction degree, operating mechanism, amplitude and frequency of harmonic oscillations of the surface of the soil being compacted, vibro-shock machines with a crank-connecting rod exciter, automatic control system, control pulse distributor, process parameters sensors, on-board microprocessor controller.
Flexible concrete protective coating resistance to approach flow exposure
Authors: Yumahseva Maria , Bryanskaya Yuliya , Bryansky Ilya 
Published: July 2020

Abstract
In order to protect the bottom and coastal slopes of natural channels and artificial reservoirs from channel deformations, various shore reinforcing structures are often used. One of this structures is the universal flexible protective concrete coating. When using this kind of structures, it is necessary to take into account their interaction with the approach flow. At the flexible protective coatings operating, one of the problems is the “wrapping” of the coating body. To calculate the stability assessment of the surface coating, it is necessary to know the value of the coefficient of hydrodynamic resistance of the protective coatings. It is determined mainly by its shape. Currently, various forms of surface coatings from various materials are used. In most cases, the resistance of such structures is assumed approximately, based on the known values of the resistance coefficients of bodies of various shapes. As a rule, the elements of protective coatings have a specific form, the resistance of which must be established experimentally. The article presents the results of an experimental determination of the hydrodynamic drag coefficient of a universal flexible concrete protective coating (a universal flexible protective mat) on aerodynamic and hydraulic experimental stands. Used laboratory equipment with basic operating characteristics, examples of experimental models, and basic operating conditions during experiments are described. It is shown that the value of the coefficient of hydrodynamic resistance decreases with increasing Reynolds number. The obtained values of the hydrodynamic resistance coefficient in some cases exceed the values recommended for calculating the maximum permissible flow velocity when assessing the stability of a protective coating. It is concluded that it is necessary to experimentally evaluate the hydrodynamic resistance coefficient for each model of protective coatings. The recommended value of the hydrodynamic resistance coefficient for the studied modification of a flexible protective concrete coating is established.
Theory of stress-strain state of concrete faced rockfill dams
Authors: Sainov Mikhail 
Published: July 2020

Abstract
In spite of the fact that concrete faced rockfill dams began to be used long ago; their designing is based on empirical approaches and there is still no common theoretical concept about peculiarities of their operation. With the aid of numerical modeling the author studied conditions of forming stress-strain state (SSS) of a concrete face with consideration of impact of various factors. The used methodology of analysis took into account operation of the face not as that of the plate but as a 3D structure interacting with the dam body in a complicated way. This permitted obtaining new knowledge about the face operation. It was revealed that friction farces at the contact of the face with the dam body play the main role in SSS formation. Due to friction the concrete face perceives not only deformations of cross bending but also longitudinal forces and deformations of longitudinal bending. The most dangerous is the face lower section where the face is subject to tensile longitudinal force and longitudinal bending, which may result in appearance of transversal cracks in the face. Considerable compressive forces perceive the face in the direction from the bank to the bank. The new theoretical concept about the concrete face SSS dictates reconsideration of approaches to designing of concrete face rockfill dams. For decrease of tensile longitudinal force, the pattern of rockfill zoning in the dam body should not allow considerable difference in deformation of the dam zones; also it is necessary to decrease friction on the contact of the face with the under-face zone. “Soft” vertical joints should be arranged to decrease compression in the face in the direction from one side to the other side.
The methodology of geo-information monitoring system of oil pollution distribution in sandy soils near fuel station
Authors: Man’ko Arthur 
Published: July 2020

Abstract
This article considers the results of studies of possible permeability coefficient in sandy soils of oil products sold in bottling at fuel stations. Based on the results of the obtained data, a method of geo-information monitoring of the environmental condition of the existing or newly built fuel station of the environment is created to minimize the risk of possible pollution of the environment (soils, above-ground and underground waters).
Evaluation of Current Standards in Designing Cold-rolled Aluminium Channel Beams
Authors: Hieu Pham Ngoc , Hung Pham Cao , Rasmussen Kim J R 
Published: July 2020

Abstract
Cold-rolled aluminium alloy sections have been well known as new products of BlueScope Permalite, and have been produced by utilising the existing rolling system for cold-formed steel sections to successfully roll-form Channel and Zed sections in Australian market. The roll-forming approach is proven to be faster and more cost-effective as compared to the conventional extrusion method. This method has attracted the attention from the manufacturers and users as well as researchers which resulted in the ARC Linkage Research Project-LP140100863 grant funded by the Australian Research Council and BlueScope Permalite to perform research on these types of cold-rolled aluminium sections. One of the objects in this project is to evaluate the application of current design standards in designing cold-rolled aluminium alloy members which are necessary to propose modifications in Aluminium design standards. This paper presents the applicability of current Aluminium design standards including Australian Standard, American Specification and Euro code in designing cold-rolled Aluminium Alloy Channel Beams by using reliability analysis.