The present article discusses some problems of renovation and modernization of large-panel residential buildings built in the postwar period in Yerevan. The analysis of the current situation showed that today these buildings have many problems related to their functional and aesthetic aspects of quality and become obsolete. The floor plans don’t satisfy modern functional requirements of inhabitants: similar and repeatable types of buildings became the reason of large arrays of monotonously built up districts with low indicators of quality. Furthermore, there are many low quality extensions and add-ins to the buildings made by inhabitants without control, which destroy the architectural appearance of habitat. Yard places of large-panel residential buildings are occupied by car parks and road travel, buildings are cut off from courtyard areas, which as a consequence don’t meet tsocial and functional requirements of the people. The consideration of the international experience of large-panel old housing renovation in European countries has shown that the main activities include improving the energy efficiency of residential buildings with removing heat loss and using solar panels, contrast changes in architectural appearance with large terraces, loggias, using wide range of colors, add-in attics and enlarging the height and the use of space-planning decisions to increase the living space. Analyzing the current situation of the housing and the international experience of modernization the concept of complex modernization of large-panel buildings was offered, which suggested bringing it to life on three main levels of habitat: apartments, building shapes, residential environment and areas. The main goals of the concept are increasing the comfort of planning decisions as well as the total size of the apartment, improving architectural appearance of the building and introducing areas for public services to housing, increasing energy efficiency and creating green areas at all floor levels, achievement of individual style of the buildings and the possibility of an easy transformation, increasing the effective use and the ecological status of a yard.

The article considers the problems connected with new offers on a daylight factor design in premises with roof natural lighting system with account of lighting effect of surrounding buildings. The offers for daylight design are based on a hypothesis of possible use of some design points for side natural lighting of interiors in the design of roof natural lighting. This is connected with a need to account for a lighting effect of neighborhood buildings. This effect must be considered in the case of lighting design for underground or sub-around buildings. These theoretical offers were confirmed with practical experiment results. The problem, discussed in the article has been stated and analyzed before by a number of domestic and foreign authors. These questions arose mainly because of the broad developing activity in the construction of underground and below-ground buildings and structures, mainly bound with public premises. The need of such development can be explained by the lack of vacant city areas, especially in the central parts. Moreover, the construction methods of such a development are much simpler, as compared with traditional construction technologies of above-ground objects. As for indoor lighting conditions in the underground and below-ground buildings, the only possible way to provide sufficient lighting of interiors is an implementation of roof lighting system in the form of skylights or monitors with one-side or two-side glazing. It is obvious, however, that these roof lighting units are influenced by shadowing effect of the surrounding buildings, which can decrease the incoming light flow to the interiors. This point is the main one, which forced the authors to investigate this scientific problem.

The article describes the calculation of plates on the elastic basis, both two-layer and single-layer. The calculation is based on the solution of the differential equation of bending plate by finite difference method. The calculation results are compared with the numerical solution in the program complex. The percentage of differences of values depending on the method of division or method of solving is shown. We considered a problem when a foundation plate and a construction are plates, which are deformed together, that, in fact, corresponds to the problem of bending a two-layer plate on elastic basis. In case of a two-layer plate in order to find the solution of the problem we need to solve the equation of bending of plates that are structurally similar to the traditional, but still give different results. In solving finite difference operators derivatives are substituted into differential equation which must be in accordance with each grid point, as well as at the border. If we consider the problem in the conventional formulation, only the lower layer is bended in the plate; the analysis of the plate, which takes into account the weight of its own layers, both layers are deformed together. Also when considering a two-layer plate, the neutral layer is deposed away from the upper layer, consequently, the whole foundation plate may be in the condition of stretching. When comparing the results of analytical and numerical calculations of the values obtained in general there are little discrepancies. Thus, there is the possibility of holding combined calculation of the “structure-foundation-base system” by finite difference method using a two-layer model of a plate on elastic basis.

The author offers a classification of Finite Element formulations, which allows orienting in a great number of the published and continuing to be published works on the problem of raising the efficiency of this widespread numerical method. The second part of the article offers examination of straight formulations of FEM in the form of displacement approach, area method and classical mixed-mode method. The question of solution convergence according to FEM in the form of classical mixed-mode method is considered on the example of single-input single-output system of a beam in case of finite element grid refinement. The author draws a conclusion, that extinction of algebraic equations system of FEM in case of passage to the limit is not a peculiar feature of this method in general, but manifests itself only in some particular cases. At the same time the obtained results prove that FEM in mixed-mode form provides obtaining more stable results in case of finite element grid refinement in comparison with FEM in the form of displacement approach. It is quite obvious that the same qualities will appear also in two-dimensional systems.

Mesh cover design, a multi-element design, which ensures the correct geometrical arrangement of the elements, is a very important task. The purpose of the given article is the development of a mathematical model for selecting the geometric parameters of wooden arches with mesh orthogonal grid with different input data. In this article three variants of design were observed. The main differences between them are in the relative position of longitudinal and transverse components. When performing static calculations of such designs in order to achieve their subsequent correct assembly, the following location conditions were observed: all the items must strictly match with each other without a gap and without overlap. However, these conditions must be met for any ratio of height to the arch span, the number of longitudinal members and the thickness of longitudinal members. Inverse problems also take place. In this case, the geometric calculation is not possible to vary the cross-section elements, and the stress-strain state of the cover is provided by varying the pitch of the transverse arches of the elements, on which the geometric calculation has no influence. All this determines the need for universal mathematical models describing any geometrical parameter of the designs needed for their geometrical calculation. The basic approach for the development of such models is the use of the known trigonometric formulas, giving a complete description of the desired geometry of the arch. Finally three transcendental equations were obtained, the solution algorithm of which using Newton’s method is presented in the MathCAD. The complexity of solving such equations using the proposed algorithm in the MathCAD is reduced to a minimum.

Glass unit consists of glasses hermetically-united together. The cavity of an insulating glass unit contains a fixed volume of air (gas). In the process of production regular air with atmospheric pressure and temperature is sealed inside a glass unit. During operation the atmospheric pressure is constantly changing, but the pressure inside remains constant (at a constant temperature). A change of temperature or of the external air pressure results in a pressure difference and therefore in a load on the glass panes. The action may exceed the usual load considerably. This pressure effects the glasses of the unit, deforms them, lowers the thermotechnical properties of glass units and can lead to their destruction. The action of the inside pressure can be seen all around as convex and concaved glasses, which destroys the architectural look of buildings. It is obvious that it is incorrect to calculate thin glass plates on such a load only by classical methods of strength of materials theory. In this case we need a special calculation method. The effects of a change in temperature, altitude or meteorological pressure are easily covered by the definition of an isochore pressure. This is necessary, to determine the change of pressure due to the temperature induced gas expansion in the cavity of the insulating glass according to the ideal gas law. After the integration of the analytical plate solution and the ideal gas law, the final pressure states can easily be calculated by coupling the change of volume and the change of pressure.

Application of flexible-walled beams is rather effective because the reducing of wall thickness compared to ordinary welded beams leads to substantial reduction of metal expenditure for the walls and its more rational use. The operation experience of such beams shows that the loss of local stability of a wall takes place near bearing cross section with characteristic diagonal type of half waves, indicating, that the reason for the stability loss is in shear deformation. In plate girder with slender web big transverse forces appear, which leads to its buckling as a result of shear. One of the ways to increase stability of the parts of web near supports is to install stiffeners. In the given work the task of finding critical stresses of fixed square plate with installed inclined stiffener is considered. Investigations were performed with the help of finite element method and were experimentally checked. Recommendations were given on the choice of optimal size of the stiffener.

Biocorrosion becomes the determinative durability factor of buildings and constructions. Damages of construction materials caused by bacteria, filamentous fungi, actinomycetes constitute a serious danger to the constructions of a building or a structure and to the health of people. Biodeteriorations are typical both in old and new constructions. A great quantity of destruction factors of industrial and residential buildings under the influence of microorganisms was established in practice. Providing products and constructions based on concretes fungicidal and bactericidal properties is an important direction of modern construction material science. The most efficient way to solve this task is creation of biocidal cements. The article presents the results of experimental studies of kinetic dependences of strength gain by biocidal cements by physico-mechanical and physico-chemical analysis methods. The identical velocity character of initial hydration of the developed compositions of biocidal cements is set, as well as a more calm behavior of hardening processes at later terms. It has been established that the compositions of biocidal cements modified by sodium sulfate and sodium fluoride possess the greatest strength.

The article focuses on calculating the loss factor in the stiffness corrector of quasi-zero stiffness vibration isolator, designed for precision equipment vibration isolation from low-frequency base vibrations. Stiffness corrector is a beam with a variable cross-section and an initial curvature loaded in the middle with the transverse load. The initial curvature of the beam is determined by solving the problem of the axial deformation of the beam of variable cross-section with an axial load exceeding the critical Euler force. The loss factor of the stiffness corrector’s material is determined in accordance with Panovko energy theory. For these purposes, the elastic shape of the stiffness corrector loaded with transverse force is calculated and potential energy of the corrector, which corresponds to the prescribed elastic shape, is obtained. Loss factor is calculated by dividing the absorption coefficient of the stiffness corrector material by its potential energy for various types of cross-sections of corrector’s beams. Determination of stiffness corrector’s material loss factor is performed through several experimental investigations, in which the coefficients of the approximating function are obtained via approximation of specimen of damped oscillations.

In the article the problem of calculation of a construction basis system in case of earthquake is considered taking into account casual properties of basis soil in various points of the soil body. As a stochastic function in the calculation of linearly deformable basis, the deformation module, which accepts different values in the direction
x,
y,
z, was chosen. In the calculation of the system on non-linearly deformable basis as incidentally distributed sizes the following parameters were accepted: deformation module, shear modulus, specific adhesion, angle of internal friction. The authors of the article offer to consider initial seismic influence in the form of casual stationary process. In order to solve such problems modern software systems are proposed that solve differential equations of motion via direct integration with explicit schemes. The calculation in this case will be held on the synthesized accelerograms. A short review of the task solution of the beam lying on elastic basis, which was received by D.N. Sobolev at casual distribution of pastel coefficient in the direction
x, is provided in article. In order to define the objective, D.N. Sobolev gives expressions for a population mean and correlation function of stochastic function. As a result of the task solution population means and dispersions of function of movements and its derivatives were received. The problem formulation considered in the article is more complicated, but at the same time important from a practical standpoint.

The interaction process of a power plant building with the soil base is studied basing on mathematical modeling of the construction process of Kambarata-2 HPP, taking into account the excavation of foundation pit, the concreting schedule of the building construction, the HPP units putting into operation and territory planning. Mathematical modeling of stress-strain state of the system “power plant - soil base” in the process of construction was performed by using the computer program “Zemlya” (the Earth), which implements the method of finite elements. Such a behavior of soil was described using elastoplastic soil model, the parameters of which were determined from the results of the triaxial tests. As shown by the results of the research, the continuous change of settlement, slope, deflection and torsion of the bottom plate and accordingly change of stressed-strained state of power plant are noted during the construction process. The installed HPP construction schedule, starting from the construction of the first block and the adjacent mounting platform, is leading to the formation of initial roll of bottom plate to the path of the mounting pad. In the process of further construction of powerhouse, up to the 29th phase of construction (out of 40), a steady increase in its subsidence (maximum values of about 4.5 cm) is noted. Filling of foundation pit hollows and territorial planning of the construction area lead to drastic situation. In this case, as a territory planning points exceeded the relief, the plastic deformation in the soil evolves, resulting in significant subsidence of the bottom plate under the first block (up to 7.4 cm). As a result, the additional subsidence of the soil of bottom plate edges lead to the large vertical movement in relation to its central part and it is bent around the X axis, resulting in a large horizontal tensile stress values of Sz (up to 2.17 MPa) in the constructive elements of the upper part of the powerhouse. At the same time, the calculations performed on the assumption of instantaneous power plant construction forecast only a uniform slope of bottom plate in the direction of the headwater and do not allow us to track the process of stress-strain state of the power plant for adequate reinforcement of its elements.

The fillers together with binders take part in microstructure formation of matrix basis and contact zones of a composite. The advantage of cement matrix structure with a filler is that inner defects are localized in it - microcracks, macropores and capillary pores, as well as that their quantity, their sizes and stress concentration decrease. Structure formation of filled cement composites is based on the processes taking place in the contact of liquid and stiff phases, which means, it depends on the quantitative relation of the cement, fillers and water, and also dispersivity and physical and chemical activity of the fillers. In the article the authors offer research results of the processes of hydration and physical-mechanical properties of cement composites with fillers from the fields of the Chechen Republic. Research results of heat cement systems are presented, modified by fine fillers. Optimal composition of cement composites filled with powders of quartz, sandstone, river and a mountain limestone of different particle size composition, characterized by a high strength, are obtained.

In the process of construction ceramics production a substantial quantity of non-renewable natural resources - clays - are used. One of the ways of science development in building materials production is investigation of the possibility of regular materials production using technogenic waste. Application of coal-mining waste (technogenic raw material) in charge composition for production of ceramic products provides rational use of fuel, contributes to implementation of resource saving technologies on construction materials production enterprises. Though science development on revealing new raw material sources should be conducted with account for safety, reliability, technical, ecological and economical sides of the problem, which is especially current. The article deals with the problem of coal-mining waste usage in building ceramics production instead of fresh primary component (clay), fluxes, thinning agents and combustible additives. The interdependence between the density and shrinkage of the ceramic products and the amount and quality of coal-mining waste in its composition was established. The optimal proportion of coal-mining waste and clay in building ceramics production was estimated.

Improving physical mechanical and operational properties of concretes and other composite materials is one of the most important tasks in construction material science. At the present time various methods are applied for that, which includes the use of additives, composite binders, activated mixing water, etc. Composite construction materials based on cement binders with mineral additives are widelu used, because they possess improved physical mechanical and technological properties. Implementation of additives improve placeability and nonsegregation factors of concrete and mortar mixes, lead to compaction of concrete and mortars structure. The additives substantially lower heat generation of concretes, which is of great importance in concrete casting of large structures. The article presents the results of experimental studies of cement composites filled with powders of rocks and mixable with activated water from the deposits of the Chechen Republic. The soundness of cement compositions with the additives of mountain and river limestone, sandstone and quartz sand was established. The results of experimental studies on establishing the effect of fine and coarse aggregate on strength formation of cement composites activated by water mixing were presented.

Negative consequences of deposit development on the environment are well know. They manifest themselves most intensively in case of open-cut mining of ore minerals, which is related to the increase of rock dumps masses. The material of rock dumps and tailing dumps actively influence the state of the environment transforming the natural landscapes, first of all, as a reason of migration of waters changed as a result of their contact with mining waste. The authors give their estimation of the consequences of apatite-nephelinic ore crop in Khibini Ore District by the company “Apatit”, which includes the influence on the natural waters. The unique natural conditions of the area are the reason for high-level potential geoecological danger. The mobility of lots of toxic elements is raised because of ligand-ion OH in the waters of alkali rocks of Khibini soil.

The social and economic development of the society to a greater or lesser degree touches upon ecological questions, which include water supply conservation. Waste water treatment plays a very important role. Over the recent years in developed countries the phenomenon of suburbanization has appeared. It means growth and development of the suburban area of the biggest cities. In relation with it, it seems perspective to investigate the technologies aimed at wastewater treatment coming from small settlements. The paper considers the prospects of the use of oxidation ditches as the main biological WWTP-structures for small towns in the Moscow region. In order to study the conditions to achieve high efficiency of nitrogen removal and to investigate the rule of simultaneous nitrification and denitrification removal (SND), the laboratory-scale oxidation ditch model was made in the Laboratory of Biological methods of Wastewater Treatment of Moscow State University of Civil Engineering. The experiment lasted for 6 months and showed good results, which can be used for further studies. The Michaelis - Menten formulas for enzyme kinetics of the studied biological system were obtained.

This article gives an overview of the analytical methodology for assessing the environmental safety in construction, the existing government programs in energy saving, and the analysis of the actual state of the investigated problem, proposed a method of assessment of environmental safety efficiency criteria of a city. The analysis is based on the data on housing and communal services of the City of Moscow. As a result of the consideration of the government programs and methods of assessing the environmental security in construction the conclusion was made that none of the programs reviewed and non of the methods include consideration of the relationship between environmental parameters of environmental security and energy efficiency (indicators of them are considered separately from each other). In order to determine the actual state of environmental safety analytical review was performed of energy efficiency programs of the government in Moscow and the methods of assessing the environmental safety of a construction. After considering a methodology for assessing the environmental safety of a construction, the author proposes to use the model for determining the indicator of efficiency of the city to ensure the environmental safety of the processes of life-support of the city, which takes into account the dependence of the parameters of environmental safety and energy efficiency. The author describes the criteria for selecting thr data on energy and environmental efficiency of the city. The article shows the sequence to identify the criteria for determining the indicator of efficiency of the city. In the article the author presents the results of ecological assessment of Moscow on the energy-ecological efficiency model, using the model defined performance indicators of the city to ensure environmental safety processes of life support of the city. The model takes into account the dependence of environmental safety parameters, environmental and energy efficiency. The correlation analysis of the effectiveness of the city of Moscow, the graphs for the regression assessment models of the data are described. The coefficient of efficiency indicators correlation of city support and the coefficient of life safety in the city are calculated. Performance indicator for Moscow in 2009-2012 is defined, which reflects the dependence of the processes of life support and life sustenance of the city. The proposed approach to the assessment of environmental safety may be used in the development of governmental programs on energy saving, as well as in the preparation of regulatory documents.

Water management in sugar factories doesn’t have analogues in its complexity among food industry enterprises. Water intensity of sugar production is very high. Circulation water, condensed water, pulp press water and others are used in technological processes. Water plays the main role in physical, chemical, thermotechnical processes of beet processing and sugar production. As a consequence of accession of Russia to the WTO the technical requirements for production processes are changing. The enforcements of ecological services to balance scheme of water consumption and water disposal increased. The reduction of fresh water expenditure is one of the main tasks in economy of sugar industry. The substantial role in fresh water expenditure is played by efficiency of cooling and aeration processes of conditionally clean waters of the 1st category. The article contains an observation of the technologies of the available solutions and recommendations for improving and upgrading the existing recycling water-cooling systems of sugar mills. The authors present the block diagram of the water sector of a sugar mill and a method of calculating the optimal constructive and technological parameters of cooling devices. Water cooling towers enhanced design and upgrades are offered.

The process of organization of civil engineering provides the delivery of construction materials, equipment to the civil engineering objects in the required quantities at the specified time. Effective tool for solving this problem is logistics. The basic components of logistics costs, which occupy the largest share in the sum of all logistics costs, are transportation costs and storage costs. The civil engineering industry is very promising for the use of outsourcing. The main part of works on providing material and technical resources in most cases is transferred to the outsourcing of other companies, including the group of companies forming the holding. In large holding companies the chain of movement of materials, goods and productions: purchase of materials and goods, completion materials, production structures, storage, movement, transportation, etc. may include several companies belonging in holding. The goods can be moved from one warehouse to another, with or without change of the owner of goods. Each company is obliged to show each movement of goods in their financial accounting. During the goods’ movement within a group of companies from one storage to another, from one owner to another, the total costs of the goods rise. Sales within a group of companies lead, as a rule, to a gain by one of the companies and the logistic expenses of another company. Selling to a consumer provides a profit to the seller company. Therefore, the problem of adequate allocation of logistics expenses and profits between separate legal entity and the task of continuous accounting and control of logistics costs and earnings in large companies, is vital. The automated system for accounting and controlling of logistics costs is suggested. The developed system allows controlling logistics costs of refining, storage and transportation for each ton, pieces, linear or square meters of the shipped cargoes. The System is based on complex algorithms of distribution of the total cost to costs of objects. Some results of approbation of the System in a large metal trading company are given. The System for the generation of financial and logistic reports on flow of materials, goods and production is suggested. The System provides the greatest efficiency in case of implementation in large holding companies.