FORMATION OF THE MODERN RENEWABLE ENERGY PRODUCTION AND ITS ROLE IN THE DEVELOPMENT OF THE CONSTRUCTION INDUSTRY
Pages 5-6
DOI: 10.22227/1997-0935.2016.6.5-6
Articles count - 13
Pages - 125
Pages 5-6
DOI: 10.22227/1997-0935.2016.6.5-6
Pages 7-14
The authors considered the issues of reinforcement of embankments by high-strength geosynthetic materials. It is suggested to use flat geogrid with metal cores as a reinforcement material for constructing reinforced ground supporting walls on automobile and railway roads. The results of calculations of the volumes of horizontal displacements of the front parts of supporting walls are offered. They were obtained as a result of numerical modeling using finite element method.
DOI: 10.22227/1997-0935.2016.6.7-14
Pages 15-24
One of the disadvantages of building structures made of reinforced concrete is their considerable weight. One of the trends to decrease the weight of concrete structures, including floor slabs, is the arrangement of voids in the cross-sectional building structures. In Russian and foreign practice paper, cardboard and plastic tubes has been used for creation of voids in the construction of monolithic floor slabs. Lightweight concretes were also used for production of precast hollow core floor slabs. The article provides constructive solutions of precast hollow core floor slabs and solid monolithic slabs that were used in the construction of buildings before wide use of large precast hollow core floor slabs. The article considers the application of caisson hollow core floor slabs for modern monolithic multi-storeyed buildings. The design solutions of such floor slabs, experimental investigations and computer modeling of their operation under load were described in this article. The comparative analysis of the calculation results of computer models of a hollow slabs formed of rod or plastic elements showed the similarity of calculation results.
DOI: 10.22227/1997-0935.2016.6.15-24
Pages 25-33
The article contains the calculation of a 80-storey high-rise building on 3-component accelerograms with different dominant frequencies. The “Akhmat Tower” belongs to the complex “Grozny-city 2” and is classified as a unique construction, its height is 400 m. During the construction unique high-rise buildings and high-rise buildings in seismic areas an additional computational studies are required, which should take into account the nonlinear nature of the design. For the case of linear instrumental-synthesized accelerograms, it is necessary to apply nonlinear dynamic methods. The studies were conducted using the software LS-DYNA, implementing the methods of direct integration of the equations of motion by the explicit scheme. The constructive scheme of the building frame is braced, the spatial stability is ensured by load-bearing interior walls, columns and hard disks, and frame metal coatings. The choice of the type and dimensions of the finite element and the step of integration is due to the ability to perform calculations in reasonable time, and to the required accuracy of calculation. For this aim the issues of convergence of the solutions on a number of settlement schemes were investigated with the terms of thickened mesh of finite elements: 0.5 m; 1 m; 2 m; 3 m. As a result of the research it was obtained that the best is to split into finite elements with a characteristic size of 2 m. The calculation of the building is made on rigid foundation. The authors used accelerograms normalized for earthquakes of 8 and 9 points on the MSK-64 scale. The destruction of the elements in the process of loading, and the interaction of the elements during their contact was taken into account, i.e. the calculation was made taking into account physical, geometrical and structural nonlinearities. The article analyzes the results of the calculation. The authors evaluated the seismic stability of the building. Possible ways to improve the seismic resistance of the building are suggested.
DOI: 10.22227/1997-0935.2016.6.25-33
Pages 34-45
In the article the problem of designing pile foundations on claystones is reviewed. The purpose of this paper is comparative analysis of the analytical and numerical methods for forecasting the settlement of piles on claystones. The following tasks were solved during the study: 1) The existing researches of pile settlement are analyzed; 2) The characteristics of experimental studies and the parameters for numerical modeling are presented, methods of field research of single piles’ operation are described; 3) Calculation of single pile settlement is performed using numerical methods in the software package Plaxis 2D and analytical method according to the requirements SP 24.13330.2011; 4) Experimental data is compared with the results of analytical and numerical calculations; 5) Basing on these results recommendations for forecasting pile settlement on claystone are presented. Much attention is paid to the calculation of pile settlement considering the impacted areas in ground space beside pile and the comparison with the results of field experiments. Basing on the obtained results, for the prediction of settlement of single pile on claystone the authors recommend using the analytical method considered in SP 24.13330.2011 with account for the impacted areas in ground space beside driven pile. In the case of forecasting the settlement of single pile on claystone by numerical methods in Plaxis 2D the authors recommend using the Hardening Soil model considering the impacted areas in ground space beside the driven pile. The analyses of the results and calculations are presented for examination and verification; therefore it is necessary to continue the research work of deep foundation at another experimental sites to improve the reliability of the calculation of pile foundation settlement. The work is of great interest for geotechnical engineers engaged in research, design and construction of pile foundations.
DOI: 10.22227/1997-0935.2016.6.34-45
Pages 46-55
The problem of increasing the efficiency of the use of road construction machinery and the creation of the conditions for safe operation of machinists requires a comprehensive assessment of the production environment, taking into account the requirements of ergonomics. the results of scientific research in the field of mechanical engineering do not provide a general solution to the problem in the system “machine operator-machine-environment”, although the works of many scientists and scientists-operatives are devoted to the assessment of road-building machinery. unfortunately, the results of many authors are not still enough to comprehensively assess the working environment of operators. and in terms of construction, which supposes complex production and technical facilities, this problem becomes more acute. the main goal of ergonomics is to provide scientific management of labor, and the main task is the development of a productive, comfortable and effective human activity in the conditions of modern production. as a part of the entire national economy it can provide tangible economic benefits.
DOI: 10.22227/1997-0935.2016.6.46-55
Pages 56-62
The authors considered the gypsum binder obtained in a kettle SMA-158A in the enterprise LLC “MaykopGipsStroy”. The initial gypsum binder burnt at a temperature of 120 °Сwith the following unloading out of the kettle possessed unstable physical, mechanical and operational characteristics, that’s why the grade of gypsum binder was changed from G4-AII to G5-BII for different lots, which greatly reduced its application in the composition of dry mortars. It was stated, that instability of the features of gypsum binder is determined by the essential underburning of the system, which was characterized by residual content of calcium sulfate dihydrate in amount from 2 to 7 % by weight. In frames of the investigation the authors succeeded in raising the grade of the produced gypsum binder (from G4-5 to G6) due to optimization of the technological parameters of the burning process, as well as to stabilize the composition and features, to lay down temperature and time parameters allowing to control the technological process in order to obtain the gypsum binder with specified characteristics.
DOI: 10.22227/1997-0935.2016.6.56-62
Pages 63-79
The article studies the effect of ultraviolet radiation, salt fog, variable humidity, and sea water of the Black Sea coast of Krasnodar region near the village of Abrau-Durso on the basic physical and mechanical properties of asphalt: the average density, water saturation, tensile strength at 122 °F, 68 °F and 32 °F, on the waterproofing quality of asphalt concrete. The samples were exhibited on a pier and in the soil on the coast of the Black Sea, in the sea water and in the air 400 m away from the sea. Test specimens were manufactured in accordance with Russian State Standard GOST 12801-98. Test duration was 240 days. It is found out that sea water has a negative effect on the majority of physical and mechanical characteristics of asphalt concrete. The authors found the compositions of asphalt concrete with increased resistance to the influence of climatic factors. Higher resistance is achieved in the case of dense asphaltic concrete ballast.
DOI: 10.22227/1997-0935.2016.6.63-79
Pages 80-89
In the article the authors consider the problem of the impact of man-caused load on river hydraulics processes and on the properties of river sediments that determine river channels evolution and general ecological state of water bodies. The interrelation between ecological state of water bodies, the quality of water in them and the level of contamination of sediments was determined. It is established that the conditions of long-term aquatic life as a whole and of water quality in particular directly depend on the contamination level of sediments. It is shown that the rate and volume of sediments accumulation, as well as contamination level of sediment layers, vary throughout the lifecycle of water body, which allows using sediments as the main indicator of the ecological state of water body reflecting the level of technogenic impact on aquatic ecosystems.
DOI: 10.22227/1997-0935.2016.6.80-89
Pages 90-100
The authors substantiated the role of cognitive technologies in the process of sustainable development, including the construction and investment complex. The role of subsystem of human resources management is shown in the conditions of knowledge-based economy formation. The authors discovered the criteria of sustainable development of the economy with the focus on the innovative aspect. The methodology of using cognitive technologies is offered on the example of construction of ecological housing, which is a core direction of the sustainable development of the construction and investment complex.
DOI: 10.22227/1997-0935.2016.6.90-100
Pages 101-106
The current trends of dynamic implementation of new materials, equipment and organizational and technological solutions in the construction lead to increase of information volume. Although the great amount of information flows isn’t fixed in the final variant of design documentation or doesn’t reach the construction site as instructions. This problem is most pressing for major construction projects. The main reason for such a loss of information is inefficiency of data management. The article discusses the influence of the interaction between the participants of a construction project on the effectiveness of the use of information flows within the construction project. The article also indicates the justification of such influence for organizational and technological building project evaluation, which is formed on the basis of information flows. The basic components of the information flow and conditions of effective transfer to final recipient are given. The concept of the role of a participant of building project is introduced as social component of information flow transfer is.
DOI: 10.22227/1997-0935.2016.6.101-106
Pages 107-117
The current methods of predicting the demand of the community for the lines of technical inspection of vehicles do not fully take into account the probabilistic and statistical nature of the complaints of car owners. This results in significant mistakes in the determination of the number of such lines, accompanied by insufficient rhythm of their operation. The design errors related to the complexity of accurate account for calendar fluctuations of the number of appeals can be partially or completely eliminated by using mathematical apparatus of the queuing theory. In this case, the complex technical system is considered as an open multi-channel queuing system with limited queue length. The received flows and serviced requests are considered to be the simplest. From a practical point of view, the replacement of one type of computational model by the other allows ensuring a more sustainable mode of calculating operations using the computer. The paper also provides a calculation expression for defining the lower and upper confidence limits of the dispersion of the average values of the number of arrivals of vehicles at the technical inspection that allows setting the interval of uncertainty for searching the optimal solution.
DOI: 10.22227/1997-0935.2016.6.107-117
Pages 118-125
Insufficiency and delays of maintenance of the technical state of bridges is greatly related to work labour input, absence of adequate mechanical means and automation of the process of inspection of structures. The authors considered domestic and foreign Machinery which repair bridge structures and are used to conduct surveys, tests and special repairs on different levels, both above and below the vehicle position. The design of a machine with the main operational characteristics is presented. The defects detected during the inspection of bridges are enumerated. In the conditions of deterioration of the bridges of different structures and responding the requirements to reduce the risk level of engineering structures’ operation there is a demand in renewing the population of machines for investigation of the technical condition of automobile bridge, because of special vehicles deterioration, there is no staff of specialists who are able to solve the problems of maintenance and increasing the reliability of bridge structures to the required extend. Also the main principles of control and inspection of bridge structures include the requirements to technical equipment for measurements and testing equipment.
DOI: 10.22227/1997-0935.2016.6.118-125