215 Works

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...

Soil stabilization and foundation restoration using an expandable polyurethane resin

Mohanad Sabri, Konstantin Shashkin, Evgeny Zakharin & Aleksey Ulybin
The settlement of foundation is one of the main existing problems which face construction engineers during the construction operation processes since the design of a project and through the whole construction life and it leads to bad consequences on the construction. Many methods have been implemented during the last decades to stabilize the soil, lift basements and reduce further settlements. Some of these methods are actively used and effective while others are less effective, have...

Structurization processes of cement composites modified with electrolytic additives

Tatiana Shepelenko, Nicholas Gorlenko & Olga Zubkova
There has been research on the impact of AlCl3 and FeCl3 solutions on kinetics of cement hardening. The research was carried out in two comparative versions, one of which had the saline solutions introduced into cement as gauge liquid (“water–1% electrolytic solution”), the other had them as additives, synthesized in suspensions “cement – (water–1% electrolytic solution)”. It has been stated that the use of AlCl3 and FeCl3 solutions as gauge liquids leads to reduction of...

Гистерезис водоудерживающей способности почвы на примере песчаных почв

Виталий Викторович Терлеев, Александр Олегович Никоноров, Исса Того, Юлия Валерьевна Волкова, Роман Сергеевич Гиневский, Виктор Андреевич Лазарев, Эмиль Рамилевич Хамзин, Виталий Валентинович Гарманов, Вильфред Миршель & Лука Игоревич Акимов
Перед началом проектирования строительства необходимо исследовать гидрологические условия территории. Для этого необходимо измерить некоторые гидрофизические показатели почвы. Среди наиболее важных показателей – водоудерживающая способность. Целесообразно использовать физически-обоснованную модель для исследования сорбционно-десорбционных свойств почвы по отношению к влаге. Авторы исследовали математическую модель, которая была разработана для описания гистерезиса водоудерживающей способности. Для реализации этого исследования была использована компьютерная программа «HYSTERESIS». С помощью этой программы было проведено три вычислительных эксперимента. Полученные результаты позволяют повысить точность расчета динамики влажности...

Analytical calculation of the frame with an arbitrary number of panels

Mikhail Kirsanov
A rod model of a statically determinate planar frame with four supports is proposed. The task is to obtain an analytical dependence of the deflection of the truss under the action of various loads on the number of panels in the crossbar and in vertical support trusses. To solve the problem, the computer mathematics system Maple is used. The system of equations of equilibrium is solved in symbolic form. It is shown that for a...

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...

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...

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....

Strength of reinforced concrete beams of high-performance concrete and fiber reinforced concrete

Vladimir Travush, Denis Konin & Alexey Krylov
The strength of reinforced concrete beams made of high-performance concrete and fiber reinforced concrete was evaluated in a pure-bending test. The efficiency of using straight steel fiber in bending structures was evaluated. The fracture pattern of models was described. The results of measuring the vertical displacement and crack width are provided and compared to the rated values. The diagrams of stresses and deformation in reinforcement and concrete of models are presented, and their specific features...

Self-compacting concrete using pretreatmented rice husk ash

Roman Fediuk, Valeriy Lesovik, Alexandr Svintsov, Aleksandr Mochalov, Sergey Kulichkov, Natalia Stoyushko, Natalia Gladkova & Roman Timokhin
Self-compacting concrete was obtained by partially replacing Portland cement with a previously prepared rice husk ash Preliminary preparation included the thermal treatment of the ash under various conditions. The optimum technology of preparation, allowing to receive a homogeneous concrete mix is revealed. All concrete mixtures were designed in such a way as to have a slump flow of 680 ± 30 mm in diameter, which was achieved by using different dosages of a superplasticizer based...

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...

Hot metal droplets capture with centrifugal method

Mikhail Kitain, Kseniya Strelets & Marina Petrochenko
Weld spatter properties and ways of spatter formation were analyzed in the article. It was deter-mined that solidified spatter can be considered as an active agent in environment pollution due to high dispersion, and there is a mass excess comparing with spatter spray. Hot metal droplets were used to track the flow of jets. The major part of spatter being under solidification has the size of 200 micron by dispersion and can be picked up...

BIM технологии в оценке уровня охраны труда

Шарманов Владимир Владимирович, Симанкина Татьяна Леонидовна & Мамаев Антон Евгеньевич
В статье представлена методика мониторинга и контроля техники безопасности и охраны труда на основе современных инновационных технологий и цифровой модели строительной площадки. Мониторинг на основе BIM технологии позволяет качественно по-новому подойти к контролю техники безопасности и охраны труда на строительном объекте. Показано, что результат контроля предложенным методом в виде индекса безопасности отражает фактическую ситуацию на проверяемом объекте и даёт возможность оценить влияние опасных производственных факторов. Выявлено, что данный подход к оценке позволит оперативно реагировать на...

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...

Thermal cracking resistance in massive foundation slabs in the building period

Aleksandra Bushmanova, Yuriy Barabanshchikov, Kirill Semenov, Ayyyna Struchkova & Sergey Manovitsky
The article deals with the research of the thermal cracking resistance of massive concrete and reinforced foundation slabs of buildings and structures in the building period. The article examines the results of the analysis of the thermal stress state of a massive foundation slab with a fixed thickness of thermal insulation as well as the results of changing the minimum thickness of the insulation on a surface, providing the cracking resistance of the structures on...

Ultra-high rockfill dam with combination of the reinforced concrete face and clay-cement diaphragm

Mikhail Sainov & Vladislav Soroka
The article deals with design validation of a new type of an embankment dam structural design, i.e. rockfill dam with combination of two types of non-soil seepage-control elements – a reinforced concrete face (in the dam upper part) and a clay-cement diaphragm made of bored piles (in the dam lower part). The dam of the considered design has a number of advantages over classical structural design of concrete faced rockfill dam (CFRD). First of all,...

Flat rod systems: optimization with overall stability control

Igor Serpik, Anatoly Alekseytsev, Pavel Balabin & Natalia Kurchenko
An algorithm for discrete optimization of steel flat rod systems was developed on the basis of an evolutionary search. The task is to minimize the weight of the bars via taking into account constraints on stresses, displacements, and overall stability. The cross-sectional dimensions of the bars and the coordinates of their node connections were varied. Buckling is taken into account when stability is lost both in the object plane and out of the plane. Analysis...

Finite element models in stresses for bending plates

Yury Tyukalov
Finite element models for plate bending problems are constructed on the basis of approximations of moments fields. The bending and twisting moments are approximated in the finite element area by piecewise constant functions. The solution is based on the functional of the additional energy. Algebraic equations of equilibrium of nodes of grid of finite elements are formed using the principle of possible displacements and are included in the functional with the help of Lagrange multipliers....

Survivability of structural systems of buildings with special effects

Vladimir Travush & Nataliya Fedorova
The technique of calculation analysis of survivability of reinforced concrete statically indeterminate beams and rod structural systems of buildings and structures under emergency influences is given. The statement of the problem of the computational analysis of the survivability of such constructive systems and the algorithm for determining the survivability parameter under special influences in the form of a sudden shutdown of one of the constructions is expounded. The criteria of the bearing capacity for a...

The seismic stability of facade system with facing by composite panels

Valentina Tusnina & Denis Emelianov
The hinged ventilated facades installing is a perspective technology of buildings decoration. Suspended facade systems are widely used for construction and reconstruction of residential, administrative, public and industrial buildings. Using suspended facade systems for decorating exterior walls is helping designers to solve the problems of thermal protection and architectural and artistic expressiveness of buildings by using modern heat-insulating and decoration materials. The finishing of facades with composite panels is especially effective for buildings erected in...

Probabilistic seismic assessment of concrete frame with mass irregularity

Elahesadat Hashemi, Ali Kheyroddin & Mohsen Gerami
As mass irregular structures are more influencing on the behavior of the structures, it is investigated the effect of these irregularities according to the probabilistic approach. Comparison of seismic performance of ten regular and irregular 6-story concrete special moment frame is done, based on the Mean Annual Frequency (MAF) method. The probability of collapse in all irregular models has exceeded the 1 % that is permissible value specified in the ASCE/SEI 7-16. The largest rate...

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...

Payback period of investments in energy saving

Alexander Gorshkov, Nicolai Vatin, Pavel Rymkevich & Olga Kydrevich
Authors developed a mathematical model for estimating the discounted payback period of investments for reducing energy resources needed in building's development. Obtained equations allow calculating the projected payback period for investments in energy saving, taking into account the size of the investment, the estimated or actual value of the achieved energy saving effect, the dynamics of energy carriers tariff growth, the discounting of future cash flows, and also a value and a period of loan...

Composition and rheological characteristics of bitumen in short-term and long-term aging

Bagdat Teltayev, Cesare Rossi & Saltanat Ashimova
This paper investigates the impact of sequential short-term and long-term aging of blown bitumen of the grade BND 70/100 on its mechanical characteristics in the temperature interval from 76°С to -36 °С. Group chemical composition of the bitumen has been determined by the method of liquid adsorption chromatography by the chromatograph “Gradient M”. Short-term aging has been performed in the vertical rolling thin film oven (RTFOT) under the standard of AASHTO T 240-08, and the...

Lightweight steel concrete structures technology with foam fiber-cement sheets

Vladimir Rybakov, Galina Kozinetc, Nikolai Vatin, Viktor Velichkin & Volodymyr Korsun
Lightweight steel concrete structures (LSCS) constitute an innovative building structure type that can be used both for load-bearing and enclosing purposes. They consist of steel profile – usually galvanized and cold-bent – filled with a monolithic foam concrete with 200 kg/m3 and more density value, and with fiber cement panel sheathing. These structures can be used in industrial and civil buildings as internal and external bearing and enclosing wall structures, and as slabs. According to...

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