The article deals with the development of a mathematical model for reducing the cost of building heat storage tanks by using the refrigerating capacity of liquefied natural gas (LNG)
Keywords: liquefied natural gas, LNG, special fortifications, SPS, full isolation mode, heat storage substance, TAB
The article is devoted to the task of searching for the design solution of the structural coating plate. Structural plates are widely used to cover single-storey structures and have a wide variety of structural and architectural forms. The choice of minimum weight design is based on the VAT control method. As the regulators adopted the location of the columns and the class of steel. Depending on the number and location of the columns on which the structural plate rests, the forces in the structural elements change and accordingly the cross-sectional area and mass of the structure change. Four variants of the arrangement of the columns and three versions of the class of steel were considered. For each design variant, the design was calculated numerically, the cross-section was selected, and the mass was determined. Based on the accepted criterion of the effectiveness of the design solution - metal consumption, the most effective design solution was adopted with the arrangement of columns along the perimeter of the coating in steps of one cell.
Keywords: space grid structures for roofs, regulation of stresses, optimization, metal consumption, criterion of optimality
In the article are examined structural elements of prefabricated dwelling house with wooden frame which simplify installation process of house and reduce needs for financial, mechanical and human resources.
Keywords: wood-frame house construction, wooden structures, prefabricated house, price reduction of wooden structures
A constructive solution of the walls of wooden houses from round logs or a profiled beam, which is installed vertically (wooden element) is considered. It is proposed to arrange two longitudinal milled grooves of a rectangular shape located in the diametral plane of the section of the log for the installation of sheet plywood keys, which makes it possible to include in the joint work adjacent contiguous elements when working on bending from the plane of the wall. The variant of the strapping device, it is proposed to use metal rolling profiles of Channel and I-sections, connected with metal tube elements (box section) mounted in the corners of the frame.
Keywords: round log, profiled beam, sheet plywood keys, tubular section elements
New construction materials and products require research aimed at eliminating design and usage difficulties associated with the lack of regulatory documentation. In this article, an attempt is made to extend the effect of domestic standards on new types of sheet materials and types of nails used in wooden frame housing.
Keywords: wooden structures, nagel, wooden panels, wooden layered diaphragms, nailing connections, light frame house building
The progressive destruction has enormous economic and social consequences. The problem of finding the optimal way to protect high-rise buildings from the development of a chain of avalanche-like destruction process has become of great importance due to the increase in the height of such buildings. In this work the method of protection of buildings from progressive destruction at which the technology of amplification by means of weights and built-in power frameworks is used is investigated.
Keywords: Progressive destruction, protection of multi-storey buildings, combined reinforcement, strands, built-in power frames
Short data on efficiency of a fibrobeton on the basis of heavy quartz sand are provided in work. Taking into account existence of huge reserves of natural porous fillers (the tufa, pumice, pummitsit, etc.) in various regions of Russia and also the fillers received on the basis of industry waste the relevance of a research of a stalefibrobeton with easily concrete matrixes is proved. Experimental selection of optimum composition of concrete on the basis of tuff filler of the Kamensk field of Kabardino-Balkar Republic regarding his use as a matrix of a stalefibrotufobeton (SFTB) is executed . The picked-up structure has been used for creation of skilled combined and monolithic samples of beams which should be tested. During formation of beams control samples of a stalefibrotufobeton have been selected and tested. Results of tests of control samples for compression, stretching and a bend demonstrate that fiber reinforcing exerts significant positive effect on strength and deformativny properties of a tufobeton. Data of experimental research confirm a possibility of using tufobeton in the stalefibrobetonnykh designs.
Keywords: Stalefibrotufobeton, steel fiber, matrix, volume percent of fiber reinforcing, stretching, compression, bend, dynamic influences, zone placement
The necessity to take into account external influences from natural and climatic factors - rain, snow, saline solutions, alternating temperatures, as well as internal influences from the changing parameters of the microclimate of premises, during the operation of buildings is determined. It is shown that the capillary-porous structure of the materials of the enclosing structures (ES) contributes to the development of a number of negative processes as a result of capillary condensation, which reduce the heat-shielding and operational properties of the materials of the ES. The negative changes in the materials of ES due to capillary condensation under the influence of external and internal factors are generalized. The possibilities for reducing the negative influence of capillary condensation due to regulation of the microclimate parameters of the premises are revealed. Directions of hydrophobization of ES materials for protection against capillary condensation at external influences are established.
Keywords: enclosing structure, energy efficiency, heat protection, capillary-porous structure, capillary condensation, natural and climatic factors, microclimate, heat and moisture regime, crack formation, hydrophobization
article is devoted to a question of calculation of non-stationary temperatures in cracks of residential buildings with application of numerical methods. Special attention is paid to the causes of cracks in the houses which are in the earned additionally territories of the miner's cities. By means of the program and element system of numerical modeling ANSYS the picture of distribution of cracks on a building facade is shown. The analytical method of calculation of non-stationary air temperatures consisting in application of projective methods of Galerkin is developed for cracks. Establishment of a profile of temperature and speed of air was result of a research on the basis of what it is possible to draw a conclusion that in the presence of cracks in external walls of buildings considerable indignations of the temperature field which are localized near a crack take place, and the sizes of area of distortion are defined by the sizes of the crack.
Keywords: nonstationary temperatures, numerical modeling, crack, uneven sediment, convection, thermal inertia, thermal conductivity, temperature profile, Galerkin method, dimensionless temperature
In the article results of the analysis of analytical dependences and results of the computing experiment executed in Lyr-CAD environment are considered. The purpose of the performed work is a quantitative assessment of the reduction in strength of beams of monolithic reinforced concrete overlappings caused by errors made during the performance of reinforcement work. In particular, an increase in the thickness of the protective layer of concrete and the consequent reduction in the working height of the section are considered. The data analyzed for both reference and span cross sections are analyzed. In total, four series of samples were selected, differing in the class of concrete (B15, B20, B25 and B30). Each series consisted of 9 samples having different working height sections in the reference and span sections. The working height of the section varied from 5 to 22%. The finite element model was created in the LIRA-CAD environment. In the course of the analysis, the effect of changing the working height of the section on the area of the reference and passing reinforcement, selected for strength, was investigated.
Keywords: It is established that the degree of influence of the deviations of the position of the reinforcement from the design in the reference sections and in the span is different. The greatest danger is represented by the support sections, that is, the overlapp
Abstract: the necessity of planning and cost adjustment during construction works is substantiated. The article deals with the consequences of non-compliance with rules and building regulations, which lead to additional financial costs for repair and restoration due to the destruction of both individual structures and the object as a whole. System errors in construction technology during Foundation reinforcement and installation are revealed. Made normative calculations for the implementation of the construction project. The article consists of introduction, two parts and conclusion. In the introduction the necessity of monitoring compliance with industry regulatory legislation. In the first part of the article "cost Planning in construction" substantiates the need for business planning based on economic approaches. Options for the implementation of ecological and safe construction materials in the construction of buildings. In the second part of the article "analysis of deviations from standards in construction" a detailed study of the individual stages of design and construction of buildings, which revealed the harmful effects of both gross errors and minor deviations from the established building standards. Clearly confirmed violation of the rigidity and strength of the Foundation of the building due to non-compliance with construction technology during reinforcement and installation. The algorithm of engineering calculations for the construction of the foundations of the building: schemes of works on pouring foundations and the location of formwork elements, costing and schedule of construction works, ensuring the reliability and safety of the building during prolonged use. The conclusion contains the main conclusions of the article and recommendations on cost planning in construction. In work not only consequences of use of fire-dangerous materials at erection of walls of buildings are revealed, but also constructive recommendations based on knowledge of physical properties of the construction materials providing ecological safety are given.
Keywords: technical justification, planning, regulations, construction, Foundation, costing, heat saving, waterproofing, thermal protection, fire hazard, environmental hazard, vapor permeability
The deformation model is considered in relation to the bending elements most characteristic of partially prestressed reinforced concrete structures. The bearing capacity and deformability of partially prestressed structures are investigated. Given the criteria of strength of compressed concrete that meets the attainment of the ultimate strain in the compressed concrete, as well as stretched in the longitudinal reinforcement, characterized by the achievement of the ultimate strain either in stressed or non-stressed reinforcement. The analysis of the calculation results of the strength and deformability of partially prestressed structures under short-term and long-term effects of the load on the deformation model and the norms. It is shown that the deformation model accurately estimates partially prestressed reinforced concrete elements with different types of loading for any combination of tensioned and non-tensioned reinforcement by strength and deformation.
Keywords: partially prestressed elements, deformability, strength, non-stressed reinforcement, state diagrams, deformation model
The calculation by various methods and comparison of the economic efficiency of the use of metal, reinforced concrete and pipe-concrete columns during the development of the reconstruction project of the production building are considered. A technical and economic comparison is made for the following parameters: the mass of steel and concrete; cost of basic materials; labor intensity and cost of production. Analysis of options for calculating building structures can help in choosing the way to restore the operational reliability and load-bearing capacity of reinforced concrete compressed elements.
Keywords: concrete, pipe-concrete, load-carrying capacity, I-beam column, reinforced concrete, building structures, reinforcement, constant load, strength, operational reliability, deformation
To ensure sufficient strength, stability of buildings and structures, the possibility of their further normal operation, as well as during reconstruction, when it is necessary to increase the loads on existing structures, it is necessary to strengthen the damaged structures. Ways of strengthening and repairing damaged structures of buildings and structures can to a great extent differ both in technical and economic indicators and in the convenience of implementation, so that their proper choice in each particular case is extremely important. The article considers options for strengthening load-bearing building structures and verified computations for load-carrying capacity taking into account additional loads. The technical and economic comparison of the amplification variants in terms of the following parameters is made: the mass of the amplification elements; the cost of the basic materials needed to strengthen; labor intensity and cost of production; labor intensity and cost of performance of works on strengthening. Analysis of options for strengthening load-bearing building structures can help in choosing the method of reinforcing the load-bearing capacity of reinforced concrete bending elements.
Keywords: bearing capacity, reinforced concrete structures, reinforcement, constant load, strength, operational reliability, deformation
The article is devoted to the study of the location of buildings in the city of Rostov-on-Don,with considering the town-planning aspects of planning urban areas. In the process of research, a geoinformation database was created with the criteria for the location of residential buildings in various geological risk zones. As conclusions to the article, an analysis was carried out with the identification of the location of buildings in complex geological and environmental conditions within the city of Rostov-on-Don.
Keywords: Urban construction, density of construction, engineering and geological conditions, territorial planning, geoinformation database
To solve the economic, technical, environmental and social problems of the region, it is expedient to create a regional inter-branch finance and construction forestry cluster (IFSLP). The creation of a regional IFSLP facilitates the most effective use of the integration process in the allocation of investment resources in the region. Cluster education allows: - to create investment attractiveness of the region; - to organize new jobs - to attract young professionals with higher education - to use innovative developments - to increase deductions to the local budget - to clean the forest from dead wood and substandard timber, to generate heat and electricity, - to create a competitive export product.
Keywords: resource-producing complex, regional interindustry financial and construction forestry cluster, innovation, investments, forestry direction, construction materials
This paper discusses features of development of design documents for new construction of motor roads. Lists the main stages of project development from inception of technical specifications for design work to delivery of documentation to the customer. The contents of the project documentation for car winter roads are indicated, with a description of each section. It is important to approach the development of project documentation with special care and responsibility, since sometimes even the slightest mistake can lead to serious consequences during the construction and operation of the facility. At each stage of documentation development, much time and effort is expended, current errors are identified, sections are rechecked, therefore, from preparation an technical design assignment to obtaining a positive expert opinion, it takes an average of 1.5-2 years. Correctly designed project guarantees the safety of people, when they are on the winter road.
Keywords: winter road, design, arrangement of territory, engineering surveys, technical design assignment, section of project documentation, the stages of project development, expertise
The paper considers the actual problem of an assessment of mechanical characteristics of two-layer materials by nondestructive methods (a method of conical indentation). The calculation of the process of indentation into two-layer medium by the finite element method with ANSYS program. The influence of layer thickness on the parameters of the indentation is considered.
Keywords: conical indenter, nondestructive testing, mechanical properties, strength tests of metal, finite element method, hardness, surface hardening
The paper discusses the contemporary technologies for making glass envelopes by way of planar glazing as part of reconstruction of buildings and facilities. It is highlighted that polyvalent multi-layer external walls are considered by many scientists as a mechanism for improving energy efficiency of façade systems. Based on the analysis of the research literature, the authors also note that spider glazing is optimal for two-layered glass envelopes, as it is suitable for use as part of reconstruction of frame and frameless buildings. Adaptive façade systems are suggested to be arranged with the use of brackets having a telescopic glass holder.
Keywords: energy efficiency, reconstruction, glass envelops, adaptive buildings, translucent façade, spider glazing, glass holder
The causes of death of people during a fire, as well as the effect of toxic combustion products on the human body are analyzed. It was found out that the main problem of unhindered evacuation of people from the building is blocking the evacuation routes by smoke. Methods of fighting smoke in a fire are considered and their advantages and disadvantages are determined. One of the ways to solve this problem is ultrasonic coagulation of aerosols with subsequent precipitation. Effective coagulation of smoke in a fire can be provided by a piezoelectric ultrasonic oscillatory system.
Keywords: fire, fire safety, multi-storey public building, toxic combustion products, smoke removal, smoke deposition, high intensity ultrasonic vibrations, ultrasonic radiation, acoustic radiator, piezoelectric ultrasonic oscillatory system
In this article, problems of safety of the exploited structures of the contact network are examined. The types of contact network supports used in the construction of these structures are considered. The features of the centrifuged concrete structure formation, the reasons for the heterogeneity of the structure along the thickness of the annular section and the appearance of cracks are analyzed. There is a physical model, the use of which will allow to modify the structure along the thickness of the annular section due to directed structure formation in the process of concrete with a combined aggregate and fibrous components centrifugal compaction.
Keywords: safety of structures, contact network supports, centrifuged structures, annular cross-section, physical model of the process of compaction of concrete mixture during centrifugation, concrete with combined aggregate and fibrous component
This article describes the definition of the approximating function of deflections of building structures using the method of least squares.
Keywords: the approximation function, the least squares method, the deflections of structures, prediction of deformations, the deformation of the structures
This article deals with the history of the study of engineering-geological conditions of the territory of the Caucasian mineral waters and territory of the sanatorium "red rocks". Technical report provides details on engineering geological research on the site overhaul and reconstruction of the economic bloc, "red rocks"
Keywords: degree, engineering-geological territory conditions, geological structure, mineral water
The lack of standards for the calculation of lightweight thin-walled steel structures allowed low-quality producers to save on production, which endangered the people who exploited such buildings. The appearance of normative documents for the calculation of thin-walled structures entails responsibility for the affirmers of these normative documents. In Russia, such norms appeared relatively recently and the purpose of this study was to compare domestic normative methods of calculation with non-significant ones. During the presentation of the study, the concept of a reduced (effective) section of a beam when working on bending was considered. Also, the same stages of the calculation methods were noted, indicating the places where the methods differ in their opinions. The result of this study is a comparison table for the basic geometric characteristic for obtaining the bearing capacity of an effective torque element of resistance. An analysis was carried out and a conclusion was drawn on these values.
Keywords: steel structures, light steel thin-walled structures, thin-walled beams, reduced cross-section, bending work, C-shaped profile, effective cross-section, effective area, effective resistance moment
In this paper, it is proposed to update the values of the bearing capacity of the hinge attachment of the beams to the columns on 2 bolts. A comparative analysis of the bearing capacity of the assembly presented in the 2.440-2 release 1 series and calculated according to modern building codes is carried out. Five calculation formulas were obtained for the five possible limiting states of the node. A table with the values of the limiting forces perceived by the connection is presented. A possible variant of improving the assembly is presented, by including a support table in the work.
Keywords: bearing capacity, metal structures, hinged unit, structural solution, connection of elements, limit state