215 Works

Lifetime of earth dams

Tamila Titova, Rasul Akhtyamov, Elina Nasyrova & Antonia Longobardi
The level of safety of small earth dams, operating without staff and measurement and control equipment, are considered in this study. Approach enabling the possibility to define the finite lifetime (Tf) of a small earth dam here presented. The proposed approach does not require any variables monitoring. It is based on the definition of Tf by assessing the water impact on the small earth dams by quantitative methods of system analysis. To assess the earth...

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...

Alternative engineering of steel girder cages by geometrical methods

Andrey Chernyaev
Steel girder cages are widely used as plant buildings ceilings, bridge vaults, locks of hydraulic engineering constructions and other construction objects. An important task in case of their designing is the search of the most economic constructive decision with the smallest amounts of material. Therefore the great value in construction mechanics is attached to the development of methods of search of the most rational and optimal constructive solutions. The new technique of alternative engineering of...

Performance characteristics of differentially quenched rails

Sergey Kosenko & Sergey Akimov
With the development of railway transport, the train speed, the traffic intensity, and the axle load all permanently increase in magnitude. This increase adversely affects the rail operation. The quantity of rail defects and, especially, the rate of rail-head surface wear both show an increase. Such service conditions require an enhanced mechanical strength of rails, their enhanced resistance to wear, and prolonged service life. In the present study, we analyze the operation performance of modern...

Productivity of microalgae as biofuel for bioadaptive systems of facades

Ekaterina Zalata, Iurii Shavrov, Kseniya Strelets & Maria Emelyanova
Microalgae are one of the promising fuel sources and many specialists associate it with the future of alternative energy. A promising area of application of photobiological devices is their conjugation with the architectural covers of a building and formation of bio-adaptive facades. The determining criteria for the organization of the microalgae biomass production process in the facade structure is solar radiation, ratio of light and dark growth phase and ambient temperature. The goal of this...

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...

Ultra-light hybrid composite wood-polymer structural materials in construction

Aleksandr Rassokhin, Andrey Ponomarev & Oleg Figovsky
In the 21st century, wood construction is again widespread. Industrial wood ceased to be perceived as a material for household buildings and low-rise rural houses and began to be used in the construction of large-span, high-rise and unique buildings and structures. The paper analyzes the use of wood for the construction of large-span, high-rise and unique buildings and structures. The results of experimental studies of hollow wooden parts, developed by the authors, impregnated with epoxy...

Метод управления освоенным объёмом в контроле сроков проекта

Анна Викторовна Вахрушкина, Анастасия Вячеславовна Мишакова & Ксения Дмитриевна Борщева
Статья посвящена методу управления освоенным объёмом, в ней описаны основные инструменты данного метода, особое внимание направлено на показатели отклонения сроков проекта. Также выявлены причины отказа от использования метода на практике. Выявлена основная проблема метода управления освоенным объёмом – невозможность его применения для контроля сроков проекта, проанализированы пути решения этой проблемы, предложенные У. Липке. В качестве примера был рассмотрен проект, состоящий из 8 работ. Было проанализировано три случая возможного разделения затрат между критическими и некритическими работами....

The deflection of spatial coatings with periodic structure

Mikhail Kirsanov
The scheme of the statically determinate spatial truss is proposed. Rectangular truss has a vertical supports on the sides and loaded uniformly at the nodes by the vertical forces. The forces in the rods and supports are determined using cut nodes method. The dependence of the deflection mid-span on a number of panels is obtained. A generalization of the particular solutions on an arbitrary number of panels obtained by the method of induction. All transformations...

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...

Влагоперенос в вентилируемом канале с нагревательным элементом

Елена Александровна Стаценко, Татьяна Александровна Мусорина, Анастасия Федоровна Островая, Вячеслав Янушевич Ольшевский & Антон Леонидович Антуськов
В данной статье изучается явление влагопереноса в вертикальном вентилируемом канале. Определяются параметры конструкции НВФ, оказывающие влияние на скорость влагопереноса. Необходимо иметь h ≤ L/25 ≈ 8 см. Наибольшее движение воздуха создается в конструкции с открытыми рустами. Выявлено оптимальное расположение источников тепла по высоте канала, а также их выгодные сочетания с точки зрения процесса высушивания наружной поверхности теплоизоляционного материала. В результате исследования скорости движения воздуха по высоте вентилируемого зазора, было установлено, что на максимальной высоте скорости...

Crack self-healing in clay-сement concrete diaphragm of embankment dam

Stanislav Sosky, Natalia Orlova & Aleksej Velichko
The article presents the results of the analysis of seepage flow character in an embankment dams with impervious diaphragm made of clay-cement concrete, using the Gotsatlinskaya HPP as an example. The process of slits colmatage was considered in the clay-cement-concrete diaphragm (CCCD), that be caused in the zone of tensile forces or by seismic actions. Mathematical models build in two-dimensional and three-dimensional formulation to study the characteristics of flow in subvertical and subhorizontal cracks. By...

Strength parameters of earth dams under various dynamic effects

Mirziyod Mirsaidov, Tohirjon Sultanov, Rustamkhan Abdikarimov, Alisher Ishmatov, Bakhtiyor Yuldoshev, Elyor Toshmatov & Doniyor Jurayev
The paper provides the methods for evaluating the strength parameters of earth dams under forced oscillations. The methods of solving the problem are based on the expansion of sought for solution in terms of eigenmodes of elastic structure oscillations. Linear steady-state and unsteady forced oscillations of three different earth dams were studied with account of structural heterogeneity and viscoelastic properties of structure material under various dynamic effects. To describe the viscoelastic properties, the Boltzmann-Volterra hereditary...

Numerical simulation of ventilated facades under extreme climate conditions

Mikhail Petrichenko, Evgeny Kotov, Darya Nemova, Darya Tarasova & Vitaly Sergeev
To reduce the costs of building operation, it is necessary to provide for the use of energy-saving technologies at the stage of building design. This allows efficient use of material and energy resources, minimize costs during the design and construction of buildings and structures. One of the energy-saving technologies widely used in construction is the use of ventilated facade systems. Its application in difficult climatic conditions of many regions of Russia requires improvement and refinement...

Mechanical properties of synthetic fibers applied to concrete reinforcement

Andrey Kirsanov & Oleg Stolyarov
Short synthetic fibers are increasingly used for reinforcing of cement-based composites along with metallic and inorganic fibers. In this work, the mechanical properties of short polypropylene fibers with different structures were investigated. The main characteristics, including tensile strength, Young’s modulus, strain at maximum load, and work of rupture were determined. In addition, fiber samples were examined for creep at various loading levels up to 50 % of the tensile strength. Relationship between the creep strain...

Methods of identification of concrete elastic-plastic-damage models

Andrey Benin, Artem Semenov, Sergey Semenov, Mikhail Beliaev & Victor Modestov
The methodology for identification of mechanical characteristics of the nonlinear material model for concrete, taking into account the elastic-plastic deformation and the damage accumulation under monotonous and cyclic loading, is proposed. The using such improved models of concrete deformation is actual for carrying out finite-element computations of the most important elements of unique and responsible buildings and structures. The proposed methodology is verified for three different types of concrete (B45, B25, B5), including also their...

Aerodynamics of building structures for flue gas removal

Vadim Akhmetov, Viktor Shkadov & Pavel Konon
Natural fuel burning in modern heat power plants with flue gas formation is accompanied with harmful environmental impact and potential opportunity of acid fallout. This can lead to local or even global catastrophe under adverse circumstances. High-rise structures combining a smokestack and a cooling tower are used for ecological natural fuel burning. The most important problem of these structures design is to study gas-dynamic behavior of flue gas mixing with warm ambient air flow during...

Seismic stability of a tsunami-resistant residential buildings

Tatiana Belash & Anton Yakovlev
We have analyzed data on the mechanism of tsunami waves formation and destruction caused by thereby, and also have summarized recommendations on tsunami-resistant construction. For reduction of damage and loss from strong earthquakes and high tsunami waves, hereon the solution for tsunami protection of the construction area is proposed in which small typical residential buildings are located in the upper part of the motor road trestle. At such solution, residential buildings are “torn off” from...

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...

Engineering solutions for the social housing, integrated into urban environment

Daria Zaborova, Kseniya Strelets, Jose Del Carmen Bonivento Bruges, Margarita Asylgaraeva, Marcelo De Andrade Romero & Claus Steffan
Deprived areas integrated into actively developing environment of the modern cities is a burning issue which is being studied in megalopolises of Latin America, Africa and Asia. Diverse controversial issues emerge in the interaction between the city community and inhabitants of the favela. The article deals with the solution for this issue based on the example of interaction between Brazilian favela “Sao Remo” and the University campus of Sao Paulo. Nowadays, this University conducts constant...

Protection of construction materials based on acrylates from biodeterioration

Nadezhda Anikina, Vasiliy Smirnov, Olga Smirnova & Elena Zaharova
The article is dedicated to the funginertness of different construction materials based on acrylates: emulsions Lakroten E-21, Lakroten E-31, Latacryl ZM-1, and Latacryl AF, as well as metacrylate, metacrylate copolymer with metacrylic acid, and n-chlorophenylmetacrylate acrylic glasses. All studied materials, except the Latacryl ZM-1 and copolymer acrylic glasses, demonstrated susceptibility to biodeterioration by microfungi. Multi-compound acrylic compositions appeared to exhibit the emergence, i.e. their funginertness cannot be predicted based on stability of their individual components....

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...

The interaction between the kaolinite or bentonite clay and plasticizing surface-active agents

Pavel Bulanov, Lenar Mavliev, Yevgeniy Vdovin & Eduard Yagund
The influence of a number of superplasticizers of various chemical bases on the physical and technical properties of clay soils has been studied. Model soils are considered as clay soils: kaolin clay with kaolinite mineral content up to 95 %, bentonite clay with montmorillonite content up to 70%. The greatest increase in the physical and technical properties of clay soils is achieved when they are modified by a polycarboxylate superplasticizer, which is due to adsorption...

Инженерная кинематическая теория в приложении к расчету свайных фундаментов

Владимир Сергеевич Коровкин
Автор предложил вариант расчета свайного фундамента с применением инженерной кинематической теории контактного давления грунта. Приведено решение по определению сил трения на боковую поверхность сваи дополнительно зависящее от размеров поперечного сечения внедряемой в грунт сваи. Описано решение по определению реактивного давление грунта на острие сваи или условный фундамент для всего цикла нагрузки. Рассмотрено влияние расположения плиты ростверка в свайном основании на несущую способность конструкции. Учтено взаимное влияние свай на распределение усилий в свайном ростверке. Получено решение...

Approximated methods of estimation of the reliability of framed railway structures of railway bridges

Andrey Indeykin, Sergei Chizhov, Ekaterina Shestakova, Anatoly Antonyuk, Nikolay Kulagin, Vladimir Smirnov, Vladimir Karpov & Dmitriy Golitsynsky
The development of methods for rapid assessment of the reliability of span structures of beam railroad bridges is relevant in connection with the trend towards increasing loads from the reversing freight rolling stock and the speeds of movement on the main transport with a mixed cargo-and-passenger turnover. This problem is especially urgent for the creation and implementation of special technical conditions (STC) for the design of bridges on high-speed lines (BCM), as in Europe and...

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