CIVIL AND INDUSTRIAL ENGINEERING
Development of nanotechnologies allows to solve a number of problems of construction materials science: increase in strength, durability, abrasion and corrosion resistance that determines operational reliability of building constructions. Generally it is achieved due to nanoparticles that modify the structure and properties of the existing materials or products and are entered into their volume or on a surface layer. It’s theoretically and experimentally proved that the modified water has the bigger activity owing to the change of the ionic composition influencing the рН size and other parameters. As nanoparticles have a high level of surface energy, they show the increased tendency to agglomeration, meanwhile the size of agglomerates can reach several micrometers. In this regard an urgent task is to equally distribute and disaggregate the nanoparticles in the volume of tempering water. The experiments on studying of influence of the nanoparticles of silica distributed in volume of liquid by means of ultrasonic processing on characteristics of cement and sand solution and heavy concrete have been conducted. Nanoadditive influence on density, speed of strength development, final strength under compression of materials on the basis of cement depending on nanoadditive mass percent has been established.
The paper considers application and development of information technologies while carrying out project management in construction. Organizational and technological support of works throughout its life cycle exerts an influence on quality and efficiency of successful implementation of the construction project. In order to achieve the project goal it is necessary perfectly to organize and plan works, distribute roles and responsibilities of the project participants, regulate composition and content of the project documentation. While analyzing technical and economic indices of construction organization activity and management systems operating in these organizations, conclusion has been made that market experience in functioning of operational management systems has not been adequately applied in practice of domestic construction organizations. Thus, introduction of integrated management systems for quality, costs, time parameters pertaining to project construction, their resource support will contribute to improvement of economic situation of construction organizations. The solution consists in application of up-to-date information technologies, maximum implementation of computer systems and programs in the sphere of production, creation of application software. It has been shown that it is necessary to develop a software model that provides a possibility comprehensively to apply information technology tools for monitoring progress of construction and installation works, systematization of information technology application that allow to control key parameters of construction and installation works, improvement of system for providing actual information in project implementation process. An example of complex application of software products Primavera P6 Professional R8.3.2 and ArchiCAD 17.0.0 is given in the paper.
The aim of the study is to identify main trends in the development of space grid structures. In order to reach the purpose it is necessary to conduct a review of the known structural concepts, nodal connections and specifics of the space grid structures and to make conclusions on feasibility improvement of the considered structural concepts that make it possible to develop new solutions without disadvantages residing in the analogues. Analysis of papers written by foreign and national scientists and devoted to theoretical, numerical and experimental studies of stress-strain state, influence of different factors on it and geometrical optimization and designing of space grid structures has been conducted in order to achieve the objectives. Space grid structures and, in particular, flat double-layer grid and most frequent nodes have been studied in the paper. The paper contains a short review of the history on development of space grid structures. It has been found that a rapid development of structural designs was caused by scientific and technical progress and, in particular, improvement of physical and mechanical properties of materials, development of calculation methods, application of software systems for simulating behavior of the structure under load, which significantly increased the calculation accuracy and reduced complexity of design. It has been also established that main parameters that have influence on effectiveness of a structural design are geometric dimensions of its modular elements, ratio of its depth to the span. The world experience on development of connection components has been studied in the paper. The paper presents general classification of nodal connections. Main advantages and disadvantages of existing space grid structures are highlighted and it allows to determine possible methods for their improvement. Theoretical research has permitted to establish that the main direction of spatial grid structures improvement consists in development of new node connection types. Several methods for node improvement have been proposed while taking into account the obtained results.
Bridges are considered as the most complicated, labour-consuming and expensive components in roadway network of the Republic of Belarus. So their construction and operation are to be carried out at high technological level. One of the modern industrial methods is a cyclic longitudinal launching of large frameworks which provide the possibility to reject usage of expensive auxiliary facilities and reduce a construction period. There are several variants of longitudinal launching according to shipping conditions and span length: without launching girder, with launching girder, with top strut-framed beam in the form of cable-stayed system, with strut-framed beam located under span. While using method for the cyclic longitudinal launching manufacturing process of span is concentrated on the shore. The main task of the investigations is to select economic, quick and technologically simple type of the cyclic longitudinal launching with minimum resource- and labour inputs. Span launching has been comparatively analyzed with temporary supports being specially constructed within the span and according to capital supports with the help of launching girder. Conclusions made on the basis of calculations for constructive elements of span according to bearing ability of element sections during launching and also during the process of reinforced concrete plate grouting and at the stage of operation have shown that span assembly with application of temporary supports does not reduce steel spread in comparison with the variant excluding them. Results of the conducted investigations have been approbated in cooperation with state enterprise “Belgiprodor” while designing a bridge across river Sozh.
Traffic circulation on highways is a random process. Therefore automotive damage rate and, respectively, roads on which they are moving is subjected to regularities of random processes. Dynamic processes of vehicle-road interaction are determined to various extents by a host of factors that include road pavement evenness and characteristics of moving vehicles. For this reason the following task has been set: to reveal the most significant factors and mathematically correlate values of vehicle dynamic loads with a quality of road pavement and vehicle speed. Such task statement has not been solved adequately and this situation determines importance and novelty of the investigations in the given direction. While solving the mentioned task the investigations which have been carried out under real-life conditions and with the help of real-life objects are considered as the most reliable ones. However, preparation and execution of such experiments as needed significantly complicates their implementation. In this regard it looks rather expediential to combine a factorial experiment with the tests of a checked model while using ECM with stage-by-stage parameter fixation of working processes passing in “vehicle-road” system, comprehensive assessment pertaining to influence of the selected factors and selection of their optimum combination. Mathematical dependence has been obtained to evaluate influence of several external factors on optimization of vehicle dynamic load on the road. This component makes it possible to attain a simplified and adequate description of element interaction in “vehicle – road” system. While investigating influence of pavement irregularities on maximum dynamic loads on the road influence rate of the selected factors is determined in the following sequence: vehicle weight, pavement evenness and speed of transport facility.
Improvement of design solutions in the field of urban planning is impossible without modernization of normative and regulatory framework in accordance with modern requirements, one of which is the concept for sustainable development of the society and the concept was adopted by the United Nations. Scientifically substantiated approach to solving a problem pertaining to improvement of planning and architectural-spatial structure of small cities in Iran is impossible without taking into account provisions of the sustainable development concept. In 2006–2016 the author participated in preparation of several projects for Iranian cities and revealed main problems, faced by designers and final consumers of their products – residents of cities. Difficulties in development of these documents were caused by legislation imperfection in respect of their harmonization and validation, projecting procedure and also scientific substantiations of the adopted decisions. The author presents history of legislation in urban planning sphere and also considers a system of normative and regulatory documents that regulates issues of urban planning in Iran and main levels concerning development of urban planning documentation, analyzes three main types of urban planning in Iran (city general plan, guide-plan, detailed plan), their basic structure and their compliance with modern requirements (sustainable development concept). The main urban planning documentation problems in Iran are subdivided in three stages: development, harmonization and validation. The paper enumerates various urban planning problems in Iran (insufficient information on urbanization processes, absence of national regulatory documents, absence of evaluation methods and theoretical justifications, shortage in normative requirements) and proposes prospective directions for improving normative-regulatory framework of urban planning in Iran. The author has made an analysis of legislative acts in urban planning and various types of project documentation developed in Iran and its compliance with sustainable development concept.
ECONOMY IN INDUSTRY
When the global community entered in the XXI century world emerging economy is more clearly considered as post-industrial, where a leading sector of the economy in the GDP production is not agriculture and not even industry but services. The main productive resource in such circumstances is not natural and productive capital but human capital, which is represented by storage of knowledge and skills accumulated by a person in the process of training and previous employment. Value of this capital is directly dependent on the level of education both general and professional. Human intellect becomes a main factor of production and professional. If the level is higher it means that such person can perform more valuable types of work for expand wealth of the country and it is transformed into intellectual capital. Consequently, a special market is formed that is a market of intellectual capital. An offer in this market is represented by labor with a high level of intellectuality and innovativeness and it has, in its turn, high market value. Well-handled components of human capital contribute to scientific-technical and social progress of the society, its sustainable economic development as the main types of final products unlike with previous stages of development are information and knowledge and the main factor of economic growth is productivity of mental labor workers. It is human capital that is one of the main factors ensuring transition to V and VI technological paradigms under current conditions. These paradigms are underlying a solid foundation for formation of new intellectual and information society. New knowledge and information technologies are making a breakthrough not only in the direct production of commodities but in the non-manufacturing sector as well (education, health, trade, finance etc.).
Formation of an independent democratic Belarusian state is inextricably linked with transformations in all aspects of public life and, first of all, in economy. Economic reforms in Belarus are directed on creation of socially oriented market economic system, which will ensure the most efficient usage of resources at minimum social cost. In the social economy concepts of “equality” and “poverty” are considered as basic ones. Social security services are based on these concepts and role of the social security in any country is to reduce poverty and increase equality. In modern world poverty is uniquely associated with a low level of economic development and its eradication is the first step on the path to economic growth. As for inequality, such clear connection of this concept with economic development can not be traced. There are various theories explaining the impact of inequality on economic growth. However, they cannot be considered satisfactory because they predict opposite results. Several studies have universally postulated a security as protection of vital interests of a human being, society and State from internal and external threats. Vital interests comprise a set of needs and satisfaction of these needs reliably ensures existence and possibility of progressive development of a human being, society and State which are the main objects of the security. Presence of a hierarchical structure for organization of the system or its subsystems is an essential feature for any socio-economic system. The economy is a poly-hierarchical system. When considering the hierarchical structure of production management it is important to consider one property of the economic system that is incompleteness of information.
The article suggests an approach of solving the problem of warehouse and transport infrastructure optimization in a region. The task is to determine the optimal capacity and location of the support network of warehouses in the region, as well as power, composition and location of motor fleets. Optimization is carried out using mathematical models of a regional warehouse network and a network of motor fleets. These models are presented as mathematical programming problems with separable functions. The process of finding the optimal solution of problems is complicated due to high dimensionality, non-linearity of functions, and the fact that a part of variables are constrained to integer, and some variables can take values only from a discrete set. Given the mentioned above complications search for an exact solution was rejected. The article suggests an approximate approach to solving problems. This approach employs effective computational schemes for solving multidimensional optimization problems. We use the continuous relaxation of the original problem to obtain its approximate solution. An approximately optimal solution of continuous relaxation is taken as an approximate solution of the original problem. The suggested solution method implies linearization of the obtained continuous relaxation and use of the separable programming scheme and the scheme of branches and bounds. We describe the use of the simplex method for solving the linearized continuous relaxation of the original problem and the specific moments of the branches and bounds method implementation. The paper shows the finiteness of the algorithm and recommends how to accelerate process of finding a solution.
Logistics plays a significant role in resource provision of automobile road construction. The following specific factors have rather high influential character, namely: necessity to use various types of material resources, presence of multicomponent semi-finished products that require final preparation on the construction site, rather large linear length of objects that requires formation of logistics road-construction flow, distance from production bases of construction organizations, dependence of production on natural and climatic factors, distinct seasonality of executed works. All these conditions influence on specific organizational and economic forms of logistics processes while constructing automobile roads. In order to apply a logistics approach for organization of the automobile road construction it is expedient to make modeling of systems for supply of material resources to ensure continuous process of works. Such approach will permit to specify processes requiring optimization. The proposed logistics approach to rational organization of supply for material resources required for automobile road construction presupposes control of all operations which must be carried out on the path of material flow motion. Specific feature of supply chain of material resources in the logistics system for automobile road construction is a direct dependence of final product quality on technology compliance during execution of works which is directly connected with timely supply of materials. Optimization is achieved through selection of quantitative composition of transport facilities, improvement of their productivity and selection of rational transportation schemes using a criterion of minimum cost. Usage of mathematical apparatus allows to calculate optimal number of transport facilities in the logistics system for automobile road construction, ensuring smooth delivery of material resources to the object with due account of the required rate of construction works.
ISSN 2414-0392 (Online)
