133 Works

Dynamic programming in optimization of comprehensive housing stock modernization

Salis Bairamukov & Zurijat Dolaeva
Research in the area of Dynamic programming in optimization of comprehensive housing stock modernization has shown that there are a number of important issues that require effective and rapid solutions. The purpose of research is the organization of repair and construction works by modeling the organizational and technological solutions to the use of energy-saving technologies for the comprehensive modernization of the housing stock. The proposed method of an integrated approach to the modernization of the...

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...

Survivability criteria for reinforced concrete frame at loss of stability

Vitaly Kolchunov & Sergey Savin
Analysis of scientific publications on the assessment of resistance of structures to progressive collapse, as well as existing and projects of design codes of different countries, in particular the project of Design Code "Protection of buildings and structures against progressive collapse. The design requirements. General conclusions", shows, that the main evaluating criteria are strength parameters. At the same time, structures, which are made of high– strength materials and have small sizes of cross-sections, as well...

Energy performance of domestic hot water systems

Dzintars Grasmanis, Daniil Sovetnikov & Daria Baranova
Residential sector consumes 70 % of the district heat. The domestic hot water system consumes 27 % of the total thermal energy consumption in these buildings in Riga. According to the mandate of the European Committee for Standardization (CEN) European standards for assessment of the energy performance of buildings have been developed. CEN standards give different methods and default values for calculations and procedures for energy performance assessment. Taking into account national or regional regulations...

Critical section and critical depth in open flows finding device

Nurliza Yerzhanova, Zhassulanbay Mussin, Saparbek Dzholdasov & Aliya Altynbekova
There is theoretically shown that pressure is equal to half of flow depth at state of speed flow, i.e .It is equal to half of critical depth. Knowing it, authors offer a device that is designed to finding critical section and critical depth in open flows which are defined by consecutive measurements of dynamic pressure and depth of flow by means of the device in various cross sections and section findings where the dynamic pressure...

Diagnostics of fatigue fractures of building structures elements

Oganes Chibukhchyan, Grigor Chibukhchyan & Vardan Sogomonyan
The article deals with the issues of increasing the fatigue strength of critical parts and components of construction machines and equipment, which are more often subjected to fatigue failure under the influence of variable complex loading. A quantitative estimate of the size of the fatigue fracture zones in the parts and joints installed in the building structures and power circuits of this construction equipment has been made. A new technique for technical diagnostics of the...

Influence of heat conducting inclusions on reliability of the system “sandwich panel – metal frame”

Iuliia Vedishcheva, Michail Ananin, Mohamad Al Ali & Nikolai Vatin
The paper presents results of numerical research oriented to the influence of heat conducting inclusions on thermo-technical properties of vertical and horizontal sandwich panels. Sandwich panels consist of flat steel sheets and thermal insulation core (from foam polystyrene, foam polyurethane and rock wool). Thread forming screws, which cross the sandwich panel through its depth, and connect the sandwich panel to frame, creates the heat conducting inclusions. The numerical analysis is carried out using software ANSYS....

Influence of the compensating device parameters on the underwater pipeline stability

Ksenia Kozhaeva
The definition of rational parameters of the developed compensating device of a triangular shape by calculation and experimental investigation methods is considered in the article. The proposed compensating device with the bent taps use has a more rigid design than the compensating device in the form of a broken bolt. Consequently, the correction coefficient of the compensator form, structurally executed with the use of bent taps is received by calculation and experimental methods for decreasing...

Stress-strain state of clamped rectangular Reissner plates

Mikhail Sukhoterin, Sergey Baryshnikov & Tatiana Knysh
The paper focuses on obtaining numerical results for a rectangular Reissner plate with clamped contour under the influence of a uniform load using the iteration superposition method of four types of trigonometric series (correcting functions). The initial function of bendings is selected as a quartic polynomial which turns into zero on the contour and is a specific solution to the main bending equation. Discrepancies in rotation angles from the initial polynomial are eliminated in turn...

Dome houses made of soil-concrete based on local raw materials

Lubov Zakrevskaya, Petr Lubin, Sergey Avdeev, Igor Gandelsman & Sergey Filippov
The work presents the results of research on the strengthening of soil basement in the center of the urban nucleus of Vladimir, which are loam, sandy loam in soft-plastic state, and also sandy loam with silt. The technology of applying the strengthening composition in the soil has been developed. The results of the investigation of physical and mechanical properties of soils and their water resistance have been presented. The microstructure of the concrete has been...

Earthquake engineering optimization of structures by economic criterion

Nikolai Vatin, Andrei Ivanov, Yury Rutman & Sergey Chernogorskiy
The article deals with an economic optimization problem of structures designed on areas exposed to seismic hazard. Profit (cost-effectiveness) from building usage due its design life-cycle is considered as objective function in this optimization task. Building damage state evaluation procedure and repair cost estimation method are proposed in this study. A criterion and a variable parameter of an optimization problem is suggested here as well. There is an algorithm, which combines seismic computation results with...

Method for calculating strongly damped systems with non-proportional damping

Olga Nesterova, Alexander Uzdin & Maria Fedorova
The calculation of systems under seismic excitations is performed both dynamically by time integration and quasistatically under inertial seismic loads using linear response-spectra method (RSM). Dynamic timing calculation can be performed either using direct integration of the initial system of motion equations, or by using the spectral decomposition of motion equations by shape modes. RSM is completely based on spectral decomposition. However, the spectral decomposition was worked out only for systems with proportional damping, when...

The temperature waves motion in hollow thick-walled cylinder

Oleg Samarin
A hollow cylinder with thick walls is one of the most complex objects to calculate the un-steady temperature field, so this field is the least studied. However, such objects are found in many modern constructions of systems of generation and distribution of heat. In the proposed work it deals with the study of propagation of temperature waves in the wall of the hollow cylinder after a sudden temperature change of the internal environment, fuss-causes upon...

Expanding cements hardening within the limited deformations conditions

Igor Kharchenko, Andrey Pustovgar, Stanislav Pashkevich, Aleksey Eremin, Irina Ivanova, Yuri Bazhenov & Aleksey Kharchenko
The features of expanding cement strength and structure formation at different constrained deformation conditions were studied (without constraint of deformations, uniaxial constraint of deformations, biaxial constraint of deformations, and triaxial constraint of deformations). The study was conducted for three doses of 5 %, 15 % and 25 % of expander on the calcium sulfoaluminate basis in Portland cement of CEM 42.5 mark. For experimental data interpretation in the analysis of structure and phase composition, the...

Finite element models in stresses for plane elasticity problems

Yury Tyukalov
The solution of the plane problems of elasticity theory on the basis of stress approximation is considered. To construct the solution, the additional energy functional is used. With the help of the principle of possible displacements, algebraic equations of equilibrium of the nodes of the grid of finite elements are constructed. Equilibrium equations are included in the functional of additional energy by means of Lagrange multipliers. The necessary relations for rectangular and triangular finite elements...

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...

Strength of composite steel and concrete beams of high-performance concrete

Vladimir Travush, Denis Konin & Alexey Krylov
A brief review of the use of high-performance concrete in monolithic structures in Russia in recent years is made; the last experimental work for the study of high-performance concrete in composite steel and concrete structures is observed. Strength assessment of composite steel and concrete beams has been carried out by a pure-bending test. The models destruction pattern has been described. Vertical displacement and crack width measurement results have been conducted; comparison with the standardized values...

Temperature and velocity conditions in vertical channel of ventilated facade.

Elena Statsenko, Anastasiia Ostrovaia, Vyacheslav Olshevskiy & Mikhail Petrichenko
The most economically viable and practicable method of moisture removal from the air gap with the help of free convective air flows are presented in the article. An experiment conducted on a laboratory bench simulating a hinged ventilated facade is described. The parameters and design features of a particular building envelope are determined. Also, the impact of technological gaps – grooved lines is described, which influence the air velocity in the ventilated channel, which in...

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...

Flow states in the classical Venturi channel water gauge

Andrey Zuikov, Viktorija Bakunjaeva, Tatiana Artemyeva & Elena Zhazha
The paper relates to the field of hydraulics and is devoted to the study of fluid flow states in a non-submerged Venturi channel. The aim is improvement of the method of hydraulic calculation of the classical Venturi channel. Authors applied experimental methods with the use of hi-tech certified measurement equipment allowing for digital technology-based automated collection and processing of empirical information; calculation and analytical methods. Distribution of depths, velocities and Froude numbers in flow direction...

Burnt rock of the coal deposits in the concrete products manufacturing

Mikhail Kuz'min, Leonid Larionov, Victor Kondratiev, Marina Kuz'mina, Vyacheslav Grigoriev & Alina Kuz'mina
The paper presents the results of the comprehensive study of the composition, properties and structure of the burnt rock found at the mining dumps of Cheremkhovo coal deposit (Irkutsk region, Russia). In the course of laboratory research, which included optical crystallography, there have been established the reasons accounting for the extent of burnt rock activity when in contact with cement during the cement stone formation. The benefit of the burnt rock as an active mineral...

Construction of autonomous buildings with wind power plants

Vasily Titkov, Amangeldi Bekbayev, Toleuhan Munsyzbai & Kalizhan Shakenov
The use of renewable energy converters, including local wind power plants to provide private households and houses with electricity, is gaining popularity, especially in countries where there are appropriate state subsidies. In this paper considered approach to the use of the building roof in the conversion of the kinetic energy of the incoming wind into electrical energy by a closed wind power plant (WPP). The construction of the WPP and the roof are converted into...

Bearing capacity of pasted anchors in the masonry walls of natural limestone

Vasiliy Alekseenko, Oksana Zhilenko & Mohamad Al Ali
The joint work of pasted steel anchors and wall masonry elements from natural limestone is discussed in the article. The aim of the scientific work is the development of a technique for calculating the load-bearing capacity of anchors in masonry walls from natural limestone and the development of nomograms for the rapid evaluation of the bearing capacity of anchors. The state of the problem of the work of pasted anchors in various materials was studied....

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...

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...

Registration Year

  • 2018
    133

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  • Text
    119

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  • Magazine of Civil Engineering
    133