215 Works

Organizational and technological reliability of the construction process

Vadim Kabanov
Construction projects of buildings and structures, as well as plans of construction and installation works are often subjected to fair criticism from the Pro-producers of the work. Such criticism is that the calculated cost value and long lasting-STI CMP does not take into account the specificity of real contractors. To address these criticisms and proposals were developed for the assessment of such intensity values of SMR production, which most realistically take into account the actual...

Refined methods for calculating and designing engineering structures

Volodymyr Mushchanov, Anatoly Orzhekhovskii, Anna Zubenko & Serafim Fomenko
В статье рассмотрено совершенствование методов расчета различных конструкций инженерных сооружений, которое осуществляется на основных этапах проектирования: 1) формирование нагрузок (для конструкций вертикальных цилиндрических резервуаров); 2) совершенствование проектных решений (для конструкций жесткой ошиновки); 3) оценка надежности принятых проектных решений вероятностно-статистическим методам (на примере рамно-консольных покрытий над трибунами стадионов). Основной целью исследования, проведенного при решении первой проблемы, является улучшение метода нормирования ветровой нагрузки на поверхности цилиндрического резервуара объемом 20000–50000 м3 с учетом типа крыши (провисающей мембраны) и...

Метод расчета периода контроля оборудования инженерно-технических систем

Владимир Стальевич Солдатенко, Владимир Александрович Смагин, Ярослав Николаевич Гусеница, Василий Иосифович Гера & Тамара Николаевна Солдатенко
Рассматривается модель и процедура оптимизации периодов контроля и профилактических мероприятий применительно к оборудованию инженерно-технических систем. Данный подход реализуется на основе выполнения условия минимума средних потерь целевого использования оборудования. Указанные потери возможны из-за неоптимальной периодичности контроля и профилактики элементов инженерно-технических систем. В статье рассматривается подход, используемый в теории информации для минимизации снижения ценности информации по причине перерывов при ее передаче. Особенностью предложенной подхода является использование целочисленного квантования межконтрольных интервалов и учет случайной продолжительности периодов эксплуатации оборудования....

Shielded retaining wall in the form of substandard rack-mount frame

Aleksandra Smolenkova, Vladimir Korovkin, Nina Orlova, Kirill Ragulin & Aleksandra Kuzina
The article gives a practical implementation of the engineering method for calculation of different types of retaining walls. The main provision of the method is to provide the construction calculation model as a combination of construction elements with the respective conditions of their fixing. The calculation model of shielded retaining wall (covered type of sheet pile wharf) is proposed in the form of substandard rack-mount frame where resilient ground attachment is accepted instead of rack...

Analytical determination of thermal expansion of rocks and concrete aggregates

Aleksandr Denisov & Andina Sprince
The article provides selection and approbation of the model and the model-based method for the analytical determination of thermal expansion and rock fracturing (decompression) and concrete mineral aggregates according to the data about thermal deformations of minerals based on information of the mineral composition, the average grain fineness of minerals and the elasticity modulus of rock. To accomplish the research, the author has used two models available in scientific publications: 1. Balashov and Zaraisky Model...

Silica fumes of different types for high-performance fine-grained concrete

Aleksandr Rassokhin, Andrey Ponomarev & Oleg Figovsky
One of the most often and successfully applied admix as a part of the modified concrete is active amorphous silica fume. The increased practical interest in this admix has led to emergence in the market of various producers and also to emergence of different types (brands) of the silica fume produced from various raw materials with use of various technologies. At the same time their makeup, dispersion and content of silicone dioxide drastically ranges. It...

Методы оценки срока службы асфальтобетонного покрытия

Михаил Александрович Завьялов & Андрей Михайлович Кириллов
В предыдущих исследованиях была показана возможность учета энергетических изменений, происходящих в системе дорожное покрытие – транспортное средство, и их вклад в формирование научно обоснованной системы назначения сроков ремонтных работ. В связи с этим также перспективным является развитие результатов работ, в которых приводится анализ зависимостей термодинамических функций дорожного покрытия от времени эксплуатации. Несмотря на то, что ранее был сформулирован термодинамический подход, удобные расчетные формулы для определения межремонтного срока службы покрытия отсутствуют. На основании анализа полученных соотношений,...

Bearing capacity of facade systems fixing to sandwich panels

Alexander Galyamichev, Victoria Kirikova, Ekaterina Gerasimova & Andina Sprince
The article presents results of the experimental and theoretical research of bearing capacity determination for fixings, used for bearing and supporting brackets in facade systems with the base from sandwich panel. The experiment included the consideration of several types of brackets fixing: using self-tapping screws and threaded rods, taking into account the variation in the thickness of the bearing steel plates. The required values of the research were critical longitudinal force for the pull-out from...

Fire resistant fibre reinforced vermiculite concrete with volcanic application

Tolya Hezhev, Artur Zhurtov, Ayes Tsipinov & Sergey Klyuev
The results of studies on the development of vermiculite concrete composites with application of volcanic ash and pumice are presented. The composition of cement fibre vermiculite concrete fire resistant composites are offered, which allows reducing the consumption of Portland cement and simultaneously increasing their flame retardant properties. The use of basalt fibers in composites can improve the strength, fracture toughness and fire retardant properties of the coating due to the perception of tensile thermal stresses...

Reliability estimation of industrial building structures

Sergii Pichugin
The article is devoted to solving the problem of the reliability of industrial building structures: crane and roof beams, columns, redundant building systems. For this aim, the probabilistic method of structural reliability estimation is developed after the criterion of bearing strength, in which the main component of structure reliability is faultlessness. The method takes account of the random loads and material strength, loads joint action, the specific character of work and failure elements, nodes and...

The formation of the seabed surface relief near the gravitational object

Vladimir Lebedev, Igor Nudner, Nikolay Belyaev, Konstantin Semenov & Dmitry Schemelinin
During the interaction of waves and currents with objects established in the shallow offshore areas, scour of their base may occur. At the same time, it is always necessary to exclude the appearance of significant seabed scour near supporting parts of gravity-type platforms during the process of their design. The article presents the results of experimental studies of processes occurring under the impact of flows of various types on gravity-type structures and their foundations. The...

Filled epoxy composites based on polyfraction microcalcite

Tatyana Nizina, Julia Sokolova, Alexey Chernov, Dmitrii Nizin, Anastasya Popova & Nadegda Kanaeva
The effect of the polyfractional micromarble introduction on the change in the physical and mechanical characteristics of polymer composites based on low-viscosity epoxy binders has been studied. Evaluation of changes in compressive strength and tensile strength in bending of epoxy composites samples containing micromarble of three different fractions, depending on the degree of filling, was carried out. Using the method of least squares, mathematical dependences of the epoxy composites strength characteristics on the type of...

Method of calculating the optimal sand content in normal-weight concrete

Leonid Dvorkin
In the practice of proportioning concrete compositions, the optimum sand content in a mixture of aggregates is usually found empirically. The disadvantage of this approach is the considerable complexity and duration of the required tests. The aim of the work is to develop a calculation methodology for finding the content of sand in the normal-weight concrete, taking into account the optimality criteria given. Based on the well-known theoretical concepts, the design equations are substantiated for...

Local fuse to improve the behavior of concentric braces

Ali Kachooee, Mohammad Ali Kafi & Mohsen Gerami
The concentrically braced system is one of the most common lateral load bearing systems among steel structures. These systems have remarkable lateral stiffness and strength, but their compressive buckling prevents them from being ductile and absorbing optimal energy. In this study to solve this problem, by using numerical and experimental studies, a heuristic method is presented. In this method, a local fuse is used along the rectangular hollow section brace. This fuse is mounted by...

Track-etched membranes back-flushing and regeneration during the natural water purification

Polina Barashkova & Ludmila Molodkina
Membrane filtration is one of the main methods of local water treatment. Track-etched membranes allow to obtain high-quality purified water due to their high selectivity. During the filtration, the productivity of process can decreases due to the adsorption of components in the pores, pore blockages, formation of sediment layer above the membrane. To restore the productivity, the membrane should be flushed periodically or regenerated chemically. Comparative study of the back-flushing and chemical regeneration after natural...

Characteristics of the droplet motion of a liquid antifreeze reagent

Konstantin Mandrovskiy & Yana Sadovnikova
The object of investigation is the process of spraying of the anti-icing reagent. As an object of research, external forces are selected that affect on each drop of the reagent: counteraction forces, gravity forces, Coriolis force and centrifugal inertial forces, lifting force, frictional forces of the reagent on the surface of the working equipment: disk and blades. It is assumed that the liquid reactant is fed under pressure to the hydraulic nozzles installed in the...

Fluid filtration in the clogged pressure pipelines

Elena Loktionova & Dinara Miftakhova
Reducing of the hydraulic characteristics of pressure pipelines in the course of their operation due to corrosion, clogging and other causes leads to an increasing of operating costs. The existing information on the change in the capacity of pipelines under the influence of certain factors is currently insufficient. The aim of the work is to determine the influence of the clogging degree of the pipeline on its throughput. This paper describes the results of hydraulic...

Express-techniques in study of polluted suburban streams

KHristina Il'ina, Nadezhda Gavrilova, Ekaterina Bondarenko, Maria Andrianova & Alexander Chusov
Water samples from streams in suburban region of new builds were analyzed in order to suggest methods and parameters for pollution monitoring. Concentrations of total nitrogen (TN) varied from 0.6 to 9.0 mg/L, ammonium – from 0 to 6.8 mg/L, total organic carbon (TOC) from 8.3 to 21.1 mg/L. Electric conductivity (EC) varied from 80 to 640 mkSm/cm, optical density at 254 nm – from 0.41 to 1.07. Increased concentrations of TN and ammonium at...

Level ice forces on hydraulic structures during ice season

Valentin Politko & Izmail Kantardgi
The current study investigated the variability of the main parameters of drifting level ice during ice season and how this variability affects the ice load. The study was carried out on the example of hydraulic protective structures of the floating nuclear thermal power plant in the city of Pevek. Numerical modeling was performed to determine the ice load reduction factor for the case when the vertical wall is formed by the consolidated ice fragments on...

Расчет причальной набережной в виде свайного ростверка

Владимир Сергеевич Коровкин, Кирилл Геннадьевич Рагулин, Александра Дмитриевна Кузина, Александра Владимировна Смоленкова & Нина Сергеевна Орлова
Расчет свайной набережной ростверкого типа в виде стоечной рамы с жесткими заделками стоек, используемый в технической литературе и нормативных документах, представляет метод Н.М. Герсеванова. Перевод ручного расчета на компьютер практически сохранил существующую расчетную схему. Приведена практическая реализация, предложенного раннее инженерного универсального метода расчета причальных набережных. В предлагаемой расчетной схеме стоечной рамы вместо нижней заделки стоек принимается упругая заделка. При этом используются жесткостные характеристики грунта, в виде переменных коэффициентов постели. Получено инженерное решение определения эпюры бокового...

The efficiency of the noise barrier installed on the acoustically untreated gallery

Aleksandr Shasurin
The research is targeting at multi-level overpasses which offer one of the solutions for laying the highway in conditions of dense residential development and close proximity to bedroom communities. In terms of acoustics, multi-level overpasses are semi-enclosed structures made of metal and reinforced concrete, where a complex sound field with numerous re-reflections is formed. There is no method of calculating noise from such structures in the literature of our country, therefore forecasting sound levels in...

Granulated foam-glass ceramics for ground protection against freezing

Konstantin Ivanov
The problem of seasonal freezing and frost heaving of soils of the engineering structures foundations is considered. For the purpose of thermal protection of soils, a granular inorganic closed-porous material, named granulated foam-glass ceramic is proposed. In the laboratory modeling of seasonal freezing, the dynamics of temperature and deformation, as well as the distribution of moisture over the depth of the soil, were studied in three cases: a soil without thermal insulation, a soil with...

Workability of high rockfill dam with a polymer face

Mikhail Sainov & Andrey Zverev
The results of numerical study of stress-strain-state (SSS) of a rockfill dam with a face whose main watertight element is a polymer geomembrane. Analyses were conducted with consideration of non-linearity of contact interaction of structure elements and non-linearity of soil behavior. Bar finite elements were used for modelling of the thin geomembrane. The study was conducted on the example of Bovilla dam structural design which was built in 1996 in Albania. Initially Bovilla dam was...

Improvement of the soil deformation modulus using an expandable polyurethane resin

MOHANAD SABRI & Constantin Shashkin
Different methods are used in the field for foundations remediation and improvement of the soil properties, but every method has its advantages and limitations. Moreover, not all the existing methods are able to stabilize the soil and elevate the foundations effectively, regulating the process depending on the desired results. The settlements of the foundations of the buildings and structures lead to negative consequences and controlling the settlements is complex itself essentially in the type of...

Experimental justification of strainer meshes of NPP sump

Vladimir Shtilman, Boris Pogrebnyak, Pavel Arseniev, Yurii Shevchenko, Vladimir Kukhtevich, Aleksey Kurchevsky & Leonid Matyushev
Processes of filter meshes clogging of emergency core cooling system sump intended for cleaning water incoming in recirculation system from sump are studied. Test rig for study of hydraulic characteristics of filter elements, which is a closed circulation loop are described. Basic principles of modeling of coolant recirculation through a filter element, occurring in event of an emergency depressurization of primary circuit, and experimental research methods are presented. Dependences of pressure drop on meshes on...

Registration Year

  • 2017
    41
  • 2018
    133
  • 2019
    41

Resource Types

  • Text
    184