Masters and specialist program for scientific staff education
Pages 5-6
Articles count - 17
Pages - 195
Pages 5-6
Pages 7-20
The article includes an analysis of the influence of the natural conditions of the region on the structural and stylistic features of Arab architecture. National architecture depends on the features of natural-climatic conditions of the region: geographical location (the climate, terrain, building materials), seismic activity, geological structure. The Muslim architecture was influenced by: high seismic activity; the lack of wood; dry and hot climate; high temperature drops in the daytime and at night. These are the peculiarities of Asia. The Arab countries are located in several climatic zones: in subtropical, the Northern tropical and subequatorial zones. The climate here is hot and arid. Forests grow only on some slopes. A significant part of Africa and Arabia is situated in the area of the desert. In Syria forests are found only on the Eastern slopes of the mountains. There are stunted coniferous and deciduous trees. These trees are thin, low and unsuitable for construction purposes. In Iran forests grow on the Northern slopes of the Mount Elbrus, at the altitudes of up to 2500 m, and on the coast of the Caspian Sea. The Central Iranian plateau has almost no vegetation. There is very little rainfall (100...250 mm per year). The air cools down quickly at night. There are also large diurnal and seasonal temperature changes. Rock formation is weathered therefore the sandy-clay deposits are formed. They are suitable for making bricks. The clay in the form of bricks was used as a building material. The unfired adobe was used too. It worked rather well in dry climatic conditions. The widespread use of the adobe influenced the color of the buildings - they were the color of soil. The wood as a construction material was scarce, so in large spans domes were built. Vaults and arches were built without the use of scaffolding and cradling. This influenced their shape. Wood is only used for architectural elements of palaces (rare wooden tall columns, ceilings and window grates made of wooden elements) and for construction of ceiling of traditional houses. Thin and uneven beams were unsuitable for the interior of the palaces.
DOI: 10.22227/1997-0935.2015.2.7-20
Pages 21-37
The optimization of the construction solutions for building structures is obviously reasonable because in case of making optimal solutions the cost of construction and further operation can be essentially cut. Relatively small changes in construction solutions may lead to essential changes on the stage of construction and operation. According to the traditional approach a designer usually develops a limited number of variants, consideration of which doesn’t guarantee the closeness of the final result to optimum. That means, the problem of the development of new and optimization of the existing optimization methods for design solutions remains current. The article is devoted to the current problems of choosing the optimal design solution for steel structures of industrial buildings. The authors offered an algorithm for computer-aided design and obtained a design solution on the example of a truss implemented in PC ANSYS. As optimization variables the truss height, steel grade and element section type are considered. The algorithm allows determining the value of the minimum truss weight for trusses of various classes and types of section. Also the corresponding optimum truss height is estimated, which gives a minimum design weight for different types of sections.
DOI: 10.22227/1997-0935.2015.2.21-37
Pages 38-44
The main tasks of optimizing metal structures is reducing their materials consumption, time of production and erection. This is achieved by using thin-walled frame structures. Cold-formed profiles are some of them. The volume of such structures application in modern construction is constantly growing. At the same time it is necessary to note, that in Russia there is no regulatory base for design of structures made of cold formed profiles, because the actual operation of such constructions differs from the operation of constructions made of hot-rolled profiles. Buckling greatly influences the operation of frame structures made of cold-formed profiles. The problem connected with the resistance of compressed-bent shanks with variable inflexibility hinge-supported at the ends is under consideration. The way to calculate the critical load at which buckling of a shank happens was found out. This task solution will help to develop the normative base for designing made of cold-formed profiles.
DOI: 10.22227/1997-0935.2015.2.38-44
Pages 45-59
In the article the author offers a classification of the methods to increase the cold resistance of steel structural shapes with a focus on the regulation of local fields of internal stresses and strains to prevent brittle fracture of steel structures. The need of a computer thermography is highlighted not only for visualization of temperature fields on the surface, but also to control the fields of residual stresses and strains in a controlled element.
DOI: 10.22227/1997-0935.2015.2.45-59
Pages 60-69
In the process of operation of buildings the moisture state of enveloping structures materials is changing depending on their construction features, properties of the material, temperature and moisture conditions in the premises, climatic conditions of the construction area. Moisture mode determines the operational properties of the enveloping structures of a building. It directly influences the thermal characteristics of enveloping structure and energy efficiency of the applied materials. The analysis of the methods for calculation of moisture behavior of enclosing structures is carried out. The research relevance of operational moisture of AAC is substantiated. Experimental studies and results of the sorption moisturizing and water vapor permeability of leading marks of aerated concrete are carried out. The authors offer the results of numerical calculations of the moisture behavior of aerated concrete in the walls with mark D400 with facade thermal insulation composite systems - with external plaster layers for different climatic zones of construction.
DOI: 10.22227/1997-0935.2015.2.60-69
Pages 70-84
One of the most important issues of our time is the introduction of the resource saving technologies in the manufacturing process. Development and implementation of such technologies are constrained not only by the technical development of the industry, but also by the normative legal aspects of waste production. In order to identify all the significant factors increasing the attractiveness of resource production technologies introduction, it is necessary to examine the changes in the basic principles of the waste management systems in Russia and industrialized countries. The paper presents an analysis of the development of control systems in waste production from the stage of unmanaged education and uncontrolled waste disposal to the environment before transition to resource management. The urgency of the transition to resource management strategies in the field of waste management is discussed. As the best practice waste management deals with the experience of Germany and Austria, where individual integration elements of waste management system are implemented into the overall development strategy of the territory. In particular, it suggests that it is possible to deal more effectively with the strategic objective of minimizing the use of primary resources through better use of the resource potential of waste in the process of comprehensive utilization and recycling, including the sharing of heterogeneous waste. In Russia the implementation of such practices is difficult due to the isolation of Territorial Administration from the businesses located in the area. Basing on the analysis of the systems of waste management the basic requirements for the control system of waste management were set out in order to achieve environmental targets, efficient environmental management and sustainable development of the area. Control systems in waste management must meet the following requirements: be environment-friendly (to ensure an acceptable level of technological environmental load generated during the waste management); preventive (provide conventional hierarchical order of waste management); integrated into the overall strategy for environmentally friendly state and further sustainable socio-economic development of the territory.
DOI: 10.22227/1997-0935.2015.2.70-84
Pages 85-92
During proving ground tests there were revealed regularities of fire suppression in enclosed space by high expansion foam using the method of volumetric filling. It is shown that the structure of a dispersed phase, particularly of smoke, has a great influence on the resistance of foam to destruction. The impact mechanism of smoke components on the formation of high expansion foam basing on the condition of integrity preserving of foam agent water solution films is considered. A short description of the interaction of smoke components with foam is given. The influence of concentration and nature of surface-active substances (SAS), concentration and nature of smoke is investigated, as well as electrokinetic parameters of foam on the foam forming process with receiving the foams of a specified structure and with control of such parameters as frequency rate, dispersion, thickness of foam films, capillary pressure in a Plateau Gibbs channels. The results of proving ground tests are presented. It is shown that application of the compositions with the highest fatty alcohols (HFA) additives as stabilizers of foam leads to increase of its stability. It is also shown that increase of foam expansion rate and dispersion of foamy bubbles leads to increase of viscoelastic properties of foam. The analysis of the material balance of high expansion foam supplied for fire suppression in enclosed premises, without account for smoke existence in it, is carried out. It is shown that the given formula includes the balance of foam accumulated and destroyed under the influence of flame and hydrostatic pressure of a solution in foamy channels.
DOI: 10.22227/1997-0935.2015.2.85-92
Pages 93-100
Partially ephemeral streams are complex objects that can still be used for water supply or irrigation of agricultural land. The problem of such streams is poorly studied, because the influence of various environmental factors complicates carrying out any experiments. Also it is not possible to make their full classification due to their very strong variability not only on a particular geographical belt, but also within separate areas of the river. All this undoubtedly complicates the task of the designers when designing the system. Creation of laboratory models, allowing us to evaluate the possibilities of a spring use for the purpose of water supply, is very promising. These watercourses have a large amount of suspended sediments, so it is not possible to use the standard scheme of water using of the coastal and fluvial water intake structures. It is proposed to organize the fight with the sediments in the flow chart of primary clarifiers, which will perform the function of settling suspensions, to facilitate the work of water treatment facilities. Also the creation of artificial prop is useful in order to achieve the required level of water in a watercourse for water organization. If under the bottom of the river there is underground water, and the permeability of the soil is good, it is possible to arrange the withdrawal of water through infiltration intakes, by setting the filter under the bottom of the watercourse with its connection to filter, from which the water will climb to submersible pumps. Additional filtration through the soil of the river bottom allows not using the scheme sumps, which significantly reduces the cost of epy incoming water treatment.
DOI: 10.22227/1997-0935.2015.2.93-100
Pages 101-109
Currently, the successful development of construction industry depends on the improved energy performance of buildings, structures and facilities, as well as on the quality assurance of the indoor climate. In view of the above, designing and operation of buildings should be aimed at the best (optimal) solution of the following objective: to ensure the set-point values of indoor climate serviced by automated climate control systems, against the minimal energy consumption. In regard of its substantive structure, this paper describes the study on the relationship between the individual parameters of indoor thermal stability and the regulatory impact of automatic control systems (ACS). We analyzed the effect of structural room characteristics on the total energy consumption of the airflow processing unit in order to ensure energy saving. The final result is illustrated by numeric simulation with the use of a developed computer program and graphic examples. The proposed method is based on the assumption that the total thermal stability of the «room-ACVS-ACS» system is defined by heat absorption index of a room and the ACS control operation. This follows directly from the back-to-back connection of units corresponding to the room and ACVS in the scheme of automatic indoor climate control. Further study allowed authors to trace the influence of structural characteristics of a room on the total energy consumption needed for air intake treatment. This can be done by applying values of the main walling area. Basing on the developed algorithm, the authors made calculations using the computer program developed in Fortran. As a result a fragments of the program are presented - calculations of the parameters’ values included in the expressions and the total specific energy consumption for heating the air intake during the heating season, under varying room geometry, as well as the graphic illustration of the obtained relationships.
DOI: 10.22227/1997-0935.2015.2.101-109
Pages 110-129
Industrial water treatment is accompanied by water industry sludge formation. A great amount of methods of industrial sludge processing and utilization has been developed. Though the majority of such waste is usually being sent to sludge storages. Sludge storages take great areas, which could be practically used, and have a negative impact on the components of geological environment. Though the compositions of such sludge is close to natural soil. The elements of a comprehensive evaluation of water-management sludge ponds as raw-material sources for soil-like recultivation materials using stepwise criteria selection are presented. A comprehensive technique of pre-utilization sludge treatment is developed. The investigation results of the main stages of treatment - dewatering, mineralization, and hardening - are given. The technique offered will enable reducing the costs of the purchase of natural soils for re-cultivation as well as reducing the waste disposal costs.
DOI: 10.22227/1997-0935.2015.2.110-129
Pages 130-140
Water disposal constructions are one of the most responsible constructions of reservoir hydrosystem, that’s why the a lot of attention was always paid to the problems of estimating and providing their reliability and safety. The most important function of such objects is providing reliability and safety of other hydraulic constructions and economic assets in afterbay and water head. The authors offer estimation method for reliability and faultless performance of reserved water disposal with erodible fuse plug on low-head water development. In order to estimate the reliability of reserved water disposal with erodible fuse plug the Bayesian treatment was used. The calculation of diagnoses (states) of reserved water disposal isoffered in case of diagnostic properties k
1 and k
2. One of the main demands placed onreserved water disposals is erosion of soil plug in case of flood discharge exeedance over the estimated frequency with the full opening of the waste sluice.
DOI: 10.22227/1997-0935.2015.2.130-140
Pages 141-152
In the article the authors analyze numerical modeling results of the stress-strain state of a combined dam created by construction of a higher rockfill dam with a reinforced concrete face behind the downstream face of the concrete dam. The analysis was conducted on the example of the design of 150 meter high New Exchequer dam (USA). Numerical modeling was conducted with consideration of non-linearity of soils deformation as well as non-linear behavior of the interaction “concrete - soil”, “concrete - concrete”. The analysis showed that though in a combined dam the concrete part gets additional displacements and settlements, its stress state remains favorable without appearance of tensile stresses and opening of the contact “concrete - rock”. This is explained by the fact that on the top the concrete dam is weightened by the reservoir hydrostatic pressure. The role of rockfill lateral pressure on the concrete dam stress state is small. There may be expected sliding of soil in relation to the concrete dam downstream face due to the loss of its shear strength. Besides, decompaction of the contact "soil - concrete" may occur, as earthfill will have considerable displacements in the direction from the concrete dam. Due to this fact the loads from the earthfill weight do not actually transfer to the concrete dam. The most critical zone in the combined dam is the interface of the reinforced concrete face with the concrete dam. Under the action of the hydrostatic pressure the earth-fill under the face will have considerable settlements and displacements, because soil slides in relation to the concrete dam downstream face. This results in considerable openings (10 cm) and shear displacements (50 сm) in the perimeter joint. The results of the numerical modeling are confirmed by the presence of seepage in New Exchequer dam, which led to the necessity of its repair. Large displacements do not allow using traditional sealing like copper water stops in the perimeter joint of combined dams. The sealing should be made of geo-membrane with placement of an asphalt pad under the face. Due to bending deformations in the lower part of the reinforced concrete face considerable tensile forces may occur. It is recommended to arrange a transverse joint in this part of the face.
DOI: 10.22227/1997-0935.2015.2.141-152
Pages 153-167
Modernization and innovative and technological rearmament of a construction complex is one of the priority problems of national economy development. Development and implementation of innovative technologies in the process of creating construction production will allow improving its quality, consumer characteristics, ensuring energy efficiency and ecological safety of buildings and constructions. One of problems of innovative development of a construction complex is the problem of financing of innovative activity. In our opinion leasing is one of effective ways of its solving. In the leasing transaction the owner of an asset temporarily transfers a right to use an asset to other party. The owner of an asset is a lessor. Other party is a lessee. The lessor makes a lease for a specified time in return for a periodic rental payments from the lessee. One of the advantages of leasing is that it provides alternative to ownership. Also lessees benefit from a number of tax advantages. Leasing has many other advantages. The assessment method of the efficiency of financial leasing as a factor of innovative development of a construction complex for a lessee enterprise in comparison with the credit is shown in article. As a result of scientific research we specified the criteria of this assessment.
DOI: 10.22227/1997-0935.2015.2.153-167
Pages 168-177
The analysis of construction theory and practice shows that rational organizational and technological parameters of the construction of residential buildings should be based on the manifestation in time and space of the most important stages construction with their harmonization. Basing on the experience of normalizing the construction duration, it is advisable to express the complex of residential buildings’ construction processes by their basic stages - preparatory period, underground part, aboveground part, external engineering networks and land improvement. The main indicators of the development and implementation of optimization solutions are: the total duration of the construction, the duration of the preparation period, the duration of the construction of the underground part, the duration of the construction of the aboveground part, the duration of external engineering networks laying, the duration of land improvement. The indicators of the total duration of the construction of residential buildings, the construction the underground and aboveground parts are determined on the basis of the operation of one assembly crane on an object of up to four sections. In case of more sections two (three) cranes are considered and the total construction duration is set depending on these conditions. The duration of the construction of multisectional buildings is determined basing on the simultaneous construction of the stages or their combination with a certain time shift. However, this approach requires a significant amount of optimization solutions due to its multivariance. Therefore, in order to reduce the volume of calculations in some cases, for example, when planning the development of districts and neighborhoods, statistical methods can be used for determining the duration of the construction basing on the compilation of optimization solutions. The total duration of the construction and the duration of the main stages are multiple-choice. Therefore, variants with minimum and maximum values can be regarded as supporting. The researches showed that the difference between them is not so much in the technological scheme of construction, but in the gap between design and practical solutions. When creating an enlarged model of multisectional residential building construction we should keep in mind the following circumstances: a part of a residential building up to 6 sections is a section, and up to 4 sections - a division; selection of a division size is determined both by adjacent associated activities (sealing and embedment of joints, partitions creation, plumbing works, etc.) and economic conditions (the cost of tooling, additional financial support, etc.); technological sequence of precast concrete structures installation can be applied depending on the design and space-planning decisions; floor assembling begins with panels of external walls with significant labor input when terminating their seams; installation of panels should closely match the tolerances of bottom and top; the process of installing concrete structures should be monitored using geodetic laser technologies (LT, LN, LSZ, etc.); elevators installation is advisable to carry out at the same time with the precast concrete structures installation on the areas free of installation.
DOI: 10.22227/1997-0935.2015.2.168-177
Pages 178-186
The article presents the results of the analysis of the existing approaches to innovations evaluation in international and Russian practice. The authors examine the nature of the concept of “innovation”, especially innovation projects, methodological tools to measure various objects’ innovativeness level as well as innovative project economic efficiency assessing methods. It should be noted that at the legislative level up to date in the process of formation and implementation of capital construction projects there are no eligible requirements and assistance from public authorities to the developer for creating innovative products, providing the appropriate level of services. And if the financial indicators of the project are more or less clear, the level of innovativeness of them is much more complicated, although the requirements on the innovativeness of the projects are included in the Strategy of innovative development of Russia. The analysis shows that in Russian and international practice there are many approaches to assessing innovations, but they cannot be considered universal and they are applied differentially depending on the goals and tasks of applying the results of scientific achievements in the form of intellectual property to improve the efficiency and competitiveness of industries, products, services. In this case individual, specific evaluation method is selected and implemented basing on taking into account all the legal, economic, technical and other aspects. As a result, the author concluded that the innovativeness level rating requires development, which is in its analytical capabilities to provide flexible management tool, which can be applied at all the stages of the investment and construction project life cycle.
DOI: 10.22227/1997-0935.2015.2.178-186
Pages 187-195
Today, speaking about the efficiency of energy saving measures it is necessary to analyze the consequences of alternative options of the use of renewables at reconstruction and updating of housing stock from the point of view of secondary energy use and by doing that to avoid negative consequences of greenhouse gases emissions. Thus special attention is paid as a rule to residential buildings. In addition to the assessment of the ideas of housing stock and power sources updating, the cost of construction materials in reconstruction projects, various concepts of reconstruction and economic consequences of the repair of buildings is also important. As a rule, the life cycle of a real estate object is longer, than the life cycle of the production process of the goods or service occurring on this object. Careful planning of the operation program of a real estate object already at the stage of its design and also its timely modernization according to new requirements play an important role throughout the whole life cycle of an object and its long-term and effective operation. The decision on the expediency of a construction project is made on the basis of the analysis of expenses for it. In practice it is quite seldom possible to take into account all the expenses for a constructed facility, that is the expenses arising at construction, operation, the contents and service of a real estate object during its existence. Often realization of more expensive solutions at the level of construction designs and equipment leads to considerable decrease in operational costs of a real estate object. Thus, without creation of a program of operation for this object it is very difficult to prove the expediency of more expensive resources and methods at construction, then it is determined by the minimum requirements. Nevertheless, the object not necessarily has to correspond to its initial state. As a rule, after some time the use of newer technical solutions is appropriate, as well as and paying attention to the requirements, which at a new (initial) construction hadn’t been revealed yet.
DOI: 10.22227/1997-0935.2015.2.187-195