233 Works

Двусторонне облученные трековые мембраны в локальном водоснабжении

Полина Сергеевна Барашкова, Людмила Михайловна Молодкина & Мария Дмитриевна Коровина
Мембранная фильтрация является одним из основных методов, применяемых в индивидуальном и маломасштабном водопользовании. С помощью трековых мембран, обладающих высокой селективностью, можно получать очищенную воду высокого качества. Но при их использовании необходимо обеспечивать прочность трековых мембран, что является актуальной проблемой. В работе проведено сравнительное изучение процесса фильтрации природной воды с использованием стандартной трековой мембраны толщиной 12 мкм и новой, более прочной, мембраны толщиной 20 мкм, облученной с обеих сторон. Обе мембраны изготовлены НПФ «Трем» (Санкт-Петербург). Диаметр...

Determination of soil deformation moduli after National Building Codes of Russia and Germany

Dietmar Keck, Julia Kalugina & Yakov Pronozin
The paper analyzes the differences in carrying out compression tests in accordance with the regulatory documents of Russia and Germany and subsequent processing of the obtained data. The paper gives the reasons for significant differences in the values of compression and design deformation moduli obtained from the compression test data in accordance with Russian and German National Building Codes. Approximate differences of the above-mentioned moduli have been revealed for various types of soil. The transition...

Natural oscillations of a rectangular plates with two adjacent edges clamped

Mikhail Sukhoterin, Sergey Baryshnikov, Tatiana Knysh & Rustamkhan Abdikarimov
We study the natural oscillations of a rectangular plate, two adjacent edges of which are clamped, and the other two are free (CCFF – plate), as an element of many building structures. The deflection function is chosen as a sum of two hyperbolic trigonometric series. Both series obey the main equation of free vibration. Meeting all boundary conditions of a problem leads to an infinite system of homogeneous linear algebraic equations with respect to eight...

Hysteresis of the soil water-retention capacity: estimating the scanning branches

Vitaly Terleev, Aleksandr Nikonorov, Roman Ginevsky, Viktor Lazarev, Issa Togo, Alex Topaj, Kirill Moiseev, Viktoriia Pavlova, Kasim Layshev, Mikhail Arkhipov, Aleksandr Melnichuk, Ielizaveta Dunaieva & Wilfried Mirschel
Designing of underground constructions, such as irrigation and drainage systems, requires engineering surveys. Such surveys include the study of the hydrological conditions of the territory, which are determined by the hydrophysical properties of soils, such as their water-retention capacity. The formation of a hysteresis loop for the soil water-retention capacity occurs because of the variability of meteorological conditions. It is almost impossible to measure all possible scanning branches that fill the gap between the main...

Vertical transport: resource by the criterion of safety

Nadezhda Sevryugina & Mikhail Stepanov
The issue of engineering systems safety in particular of vertical transportation is revealed. Inconsistency in the implementation of theoretical developments in practice is defined because of the probabilistic calculation of the parameters modeled by monotone-logical functions, when real systems are non-monotone functions. The duality of the results of the processes theoretical description is revealed. A typical algorithm of safety analysis is based on the deductive abilities of a researcher when drawing up a scenario of...

Деформации периодической фермы с раскосной решеткой

Михаил Николаевич Кирсанов & Наталия Васильевна Заборская
Рассмотрена схема плоской статически определимой фермы решетчатого типа. Ферма имеет две опоры и загружена равномерной нагрузкой по нижнему или верхнему поясу. Найдены аналитические зависимости прогиба конструкции и смещения подвижной опоры от ее размеров, нагрузки и числа панелей. Показано, что если число панелей кратно трем, то ферма кинематически изменяема, что явствует из равенства нулю определителя системы уравнений равновесия. Найдена соответствующая схема возможных скоростей узлов. Для вывода результатов использована система компьютерной математики Maple и метод индукции, ранее...

Reliability assessment of the construction schedule by the critical chain method

Marina Petrochenko, Viktor Velichkin, Yuryi Kazakov & Yevgeniya Zavodnova
Implementation of the construction projects is associated with significant current material, technical and financial costs. They increase significantly in case of the breaking deadlines the large stages of projects and putting buildings into operation. The main aim of the current research is development the new approach for reliability model of the construction schedule for increasing reliability of the calendar planning regarding the meeting the construction projects on time. The following task were solved: the model...

Interaction process on the phases interface “bitumen – dispersed phase from cement stone”

Sergei Inozemtcev & Evgeniy Korolev
The results of the study of the effect of the main properties of mineral fillers from cement stone with different degrees of hydration, phase composition and pore volume characteristics on the properties of the bitumen-mineral binder are presented. Dependencies of the influence of mineral filler on the basis of cement stone on the basic parameter of the structure of bitumen-mineral binders-the thickness of the adsorption-solvate layer of bitumen, which was established using the rheological method....

Modeling of porous material fracture

Andrey Levandovskiy, Boris Melnikov & Artemiy Shamkin
Wide use of various porous materials in construction engineering applications requires development of up to date methods of non-destructive characterization and optimization of such materials. This work explores an approach to modeling of fracture of a brittle porous material. Available 3D digital data on the specimen geometry is converted into uniform finite element mesh consisting purely of elements of cubic shape. Fracture model is based on a series of linear solutions. Thus approach to linear...

The modeling method of discrete cracks in reinforced concrete under the torsion with bending

Vladimir Kolchunov & Alexey Dem'yanov
The most famous of computer systems for the design of reinforced concrete structures in the world are taken into account only regular dispersed cracks. Completely different criteria should be used when analyzing the appearance and development of discrete cracks in reinforced concrete, the modeling methodology of which has not been developed to date. Therefore, the article provides working prerequisites, a methodology for simulating discrete cracks and calculating their rigidity. Several levels of cracking are considered....

Constructive-technological decisions in regulating the flow of atmospheric precipitation

Olga Degtyareva, Georgy Degtyarev, Nikolai Lavrov & Djouhar Aliev
Practically all sources of fresh water suitable for agriculture, water supply to the population and vacationists, as well as for industrial development on the Black Sea coast of the Caucasus either have completely exhausted themselves or are on the verge of their possibilities. Further development of the region is directly related to the resolution of this problem. The solution of the problem is possible when the system for regulating precipitation flow is implemented. The proposed...

Деформации ползучести бетона в расчетах термонапряженного состояния массивных бетонных и железобетонных конструкций

Коротченко Иван Алексеевич, Иванов Эрнест Николаевич, Мановицкий Сергей Сергеевич, Борисова Виктория Александровна, Семенов Кирилл Владимирович & Барабанщиков Юрий Германович
В статье проведен анализ термонапряженного состояния железобетонного фундамента атомной электростанции в период строительства. Представлены результаты расчета теплового напряженного состояния в массивных фундаментных плитах с учетом и без ползучести бетона. Проведен сравнительный выбор изоляции для обеспечения трещиностойкости фундаментной плиты с учетом ползучести и без. Авторами было установлено, что расчет задачи в упругой постановке приводит к существенным переоценкам растягивающих напряжений и деформаций удлинения на поверхности плиты в момент для создания максимального тепловыделения. Показано, что не учет деформаций...

Nonlinear parametric oscillations of viscoelastic plate of variable thickness

Mirziyod Mirsaidov, Rustamkhan Abdikarimov, Nikolai Vatin, Vladimir Zhgutov, Dadakhan Khodzhaev & Bakhodir Normuminov
Isotropic viscoelastic plates of variable thickness under the effect of a uniformly distributed vibration load applied along one of the parallel sides, resulting in parametric resonance (with certain combinations of eigenfrequencies of vibration and excitation forces) are considered in the paper. It is believed that under the effect of this load, the plates undergo the displacements (in particular, deflections) commensurate with their thickness. Geometrically nonlinear mathematical model of the problem of parametric oscillations of a...

Finite element analysis of crane secondary truss

Olga Tusnina
Finite element analysis of the crane secondary truss of top-blown oxygen vessel plant with the span of 36m is considered in the paper. Analysis of crane secondary truss is quiet difficult because of necessity of taking into account actual stiffness of its joints and also because of the fact that lower belt of truss made of thin-walled closed profile is experiencing restrained torsion because of eccentrically crane load acting. For these reasons modeling of crane...

Modeling the design seismic input in conditions of limiting seismological information

Tatiana Ivanova, Jhy Guan, Olga Nesterova, Sergey Prokopovich, Lybov Smirnova, Aleksandr Uzdin & Dmitry Ivashintzov
The object of the investigations is seismic input models used in structure designing under the conditions of limited seismological information. The aim of the given investigation is to propose a new variant of a seismic input model, which should be generated for the structure under consideration, taking into account main peculiarities of actual seismic excitations. The method of design seismic input generation by means of its presentation as a sum of velocity impulse and multi...

Min-cut algorithm for network schedule by merging the vertices

Yuri Kalugin, Arturas Kaklauskas & Yuryi Kazakov
The task of reducing the total duration of the project ("compression", "crashing") occurs when developing and adjusting schedules. The activities requiring crashing are determined by the minimum of added resources at the unit reduction of the schedule. The minimum cut in a critical network determines such activities. The essence of searching the minimum cut by merging vertices (edge tightening) of the critical network is presented. The procedure of selecting vertices consists of the following. Possible...

The behavior of concentric brace with bounded fuse

Mohammad Ali Kafi & Ali Kachooee
The concentrically braced system is one of the most common lateral load-bearing systems among the steel structures. This lateral loadbearing system has various apparent forms where the main characteristic of them all is their significant stiffness and lateral strength. The main weakness of the concentrically braced system is buckling in compression. This issue causes that concentric bracings have low compressive load-bearing capacity together with undesirable ductility and limited energy dissipation capacity. In this study to...

Особенности проектирования фасадных кассет из тонких керамических панелей

Галямичев Александр Викторович & Альхименко Александр Иванович
Тонкие керамические панели – перспективный материал для архитектурного использования, имеющий значительный потенциал для реализации различных интерьерных и экстерьерных решений. Применение тонкой керамики в качестве фасадной облицовки требует повышенного внимания к напряженно-деформируемому состоянию и характеру её разрушения. Основной особенностью конструкций данного типа является возможность использования на фасаде панелей с размерами, достигающими 3000х1000 мм, обладающими небольшим весом и малой толщиной (3-5 мм). Данное исследование посвящено изучению работы тонких керамических панелей под воздействием равномерно распределённой нагрузки, имитирующей ветровое...

Method for noise calculation under specular and diffuse reflection of sound

Botir Giyasov, Vladimir Ledenyov & Irina Matveeva
Selection and designing of noise protection aids in industrial buildings require numerous calculations of energy characteristics typical for noise fields of their facilities. The efficiency of designed soundproof measures is relying on their accuracy. The degree of accuracy is defined by recording completeness in the method of measurement of factors, which affect the processes of noise fields in buildings. One of these factors is the type of sound refection from barriers. The analysis of reflected...

The improving of the concrete quality in a monolithic clip

Anastasia Sychova, Larisa Svatovskaya, Dmitriy Starchukov, Valentina Soloviova & Marina Gravit
The article deals with the possibility of increasing strength, hardness, frost resistance, water and corrosion resistance of concrete. The reduction of its abrasion resistance and water absorption by creating a layer of nonorganic monolithic high-strength clip on its surface is also considered. The possibility of synthesis of such clip by impregnating the concrete surface with a Sol of SiO2 is shown and thermodynamically substantiated. The mathematical dependence reflecting the strength of concrete in such a...

Normal stresses of frost heaving as function of excess moisture

Olga Tretiakova
Tangential and normal stresses are arises foundation area from the frost heave process. Currently known is the analysis of the tangential stresses based on adfreezing of the frozen soil to the lateral surface of foundation. However, the differences in values of normal stresses may be due to the fact that no single approach to normal stress evaluation has been developed yet. The purpose of our research is to work out the analysis method of the...

Evolutionary optimization of prestressed steel frames

Anatoly Alekseytsev & Sergey Akhremenko
A method for the optimal synthesis of prestressed steel frame structures is developed. The search for a solution is being carried out by applying discrete sets of variable parameters, including cross-sections of structural rods and cross-sections of prestressing tie-rods. It is possible to vary the location of the prestressing system. To optimize the cost of the objects under consideration, an improved meth-od of evolutionary simulation has been used, including a combined scheme for constraints set...

Installation diagram of the lattice truss with an arbitrary number of panels

Mikhail Kirsanov
Hereby the diagram of a flat statically determinate regular lattice truss with the parallel chords is proposed. The task is to obtain an analytical dependence of the truss deflection and forces in the most tension and compressed bars on the number of panels. In order to solve the problem, the Maple computing mathematical system is used. We have considered the case when the lower truss chord is subject to a uniform load. The forces are...

Method of forecasting the effectiveness of cationic bitumen emulsions

Svetlana Shekhovtsova, Aleksey Korotkov & Marina Vysotskaya
Approbation of the procedure for predicting the production of effective bitumen emulsions at the stage of water phase preparation and also predicting the compatibility of the mineral aggregate and the surface-active substance used to emulsify the bitumen was carried out. As criteria characterizing the optimal composition of water phases, the following indicators were proposed: the surface tension of the water solutions under investigation and the wetting contact angle. The study of the dynamics of changes...

Показатели композитов из растительного сырья при изменениях температуры и влажности

Ирина Вячеславовна Сусоева, Татьяна Николаевна Вахнина, Андрей Александрович Титунин & Яна Алексеевна Асаткина
Композиционные плитные материалы с наполнителями из древесной стружки и невозвратных отходов переработки льна и хлопка на основе матрицы из термореактивного связующего могут использоваться в качестве строительного материала теплоизоляционного назначения. Рассмотрено влияние температуры и влажности окружающей среды на показатели композиционных плитных материалов. Приведены результаты динамики прочности и потери массы плитных материалов после циклических испытаний «замачивание – замораживание – оттаивание – сушка». Волокнистые плиты из невозвратных отходов прядения льна и хлопка имеют остаточную прочность более 60 %...

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