Moscow was not urban-developed in a day
Pages 5-10
Articles count - 14
Pages - 147
Pages 5-10
Pages 11-22
The task of comprehensive analysis presented in this article is a development of theory of calculation of shrinkage stresses in cellular concrete wall panels; such stresses occur due to carbonation of concrete because of the creep of material. Analytical dependences characterizing the influence of carbonation on the modulus of elasticity, shrinkage and creep of autoclaved cellular concrete, as well as the regularity of variation of carbonation degree as per thickness of the wall panels depending on time, were obtained. The proposed theory of calculation of shrinkage stresses in cellular concrete wall panels, with account of concrete creep, makes it possible to predict the influence of carbonation processes on crack resistance thereof, and thus to develop measures of technological and structural nature, in order to improve their operational reliability and durability.
DOI: 10.22227/1997-0935.2016.12.11-22
Pages 23-33
The boundary value problem for the Carleman system of equations is considered. The problem is investigated numerically for initial conditions which are perturbed nonnegative stationary solutions of the problem. First point of the paper is numerical investigation of solution of the boundary value problem with perturbed positive stationary solutions as an initial condition. The time dependence of the maximum deviation of the solution of the stationary solution problem of stationary solutions is investigated. The results of numerical problem solution are presented. The time dependence of the energy of perturbations of stationary solutions of the problem is presented. The solution stabilization to the stationary solution problem is obtained. The solution stabilization time is compared with stabilization time in periodic case. Second point of the paper is numerical investigation of solution of the boundary-value problem with perturbed zero stationary solutions as an initial condition. The results of numerical problem solution are presented.
DOI: 10.22227/1997-0935.2016.12.23-33
Pages 34-43
Bearing capacity for shear of assembly connections of structures made of steel thin-walled cold-formed sections is determined by the bolted connection crush strength. Results of tests of connections with a bearing surface area enlarged due to a bending of the connected element end portions and mounting of fastening elements in a type of bolts and self-drilling screws. Experimental research illustrated that the suggested approach enables to increase the bearing capacity of the connection several times over.
DOI: 10.22227/1997-0935.2016.12.34-43
Pages 44-60
This article presents the comparative results of an investigation of the low-velocity zone of the area near the housing of the PNRPU engineering faculty by active and passive methods of multichannel analysis of surface waves (MASW). MASW is a modern nondestructive method researching the soil massif. It lets to obtain profiles of transverse velocities and to find initial elastic modulus and initial shear modulus by using these profiles. The purpose of the investigation is a study of low-velocity zone by active and passive methods of MASW. The passive method of MASW has not been used previously on the territory of Russian Federation. In the passive method, geophones have been placed by “circle,” “square” and “triangle” layouts. Also, the special case of the passive method has been applied - passive roadside MASW. The telemetry system TELSS-3 has been used to register surface Rayleigh waves. The parameters of surveying system have been selected using the optimal recommended parameters and the reconnaissance surveys. Obtained seismograms have been processed using ParkSeis software. In the stage of dispersion analysis of MASW, the dispersion images have been obtained with clearly visible fundamental modes. The obtained dispersion curves have allowed making 2D profiles of shear-wave velocities for an active method and 1D profiles for passive methods of MASW. On the basis of these profiles the models of investigated soil stratification have been obtained. The presented results allow evaluating the effectiveness of the passive method of MASW as a tool for geotechnical investigations in cramped conditions, where deployment of surveying system for the active method is impossible.
DOI: 10.22227/1997-0935.2016.12.44-60
Pages 61-69
Nvestigations relating to the technical equipment of the modern building complex of Russia are carried out. Analysis of the problem showed that there is a need for management changes in the organization and management of the technical potential in these circumstances. These results suggest the need to resolve the organizational problem consisting in to develop mechanisms and management structures that can lead the technical equipment of the building complex to the state of sustainable development. Transformations must be based on the active participation of the state in this area. State regulation of the construction technical equipment should be considered as a specific control function, designed to combine the national and private interests. Recommendations to address this problem through the integration process, the formation of reasonable proportions between consumption and production of construction machinery, investment, strategic planning, taxation and other measures of state influence are made.
DOI: 10.22227/1997-0935.2016.12.61-69
Pages 70-78
A resistance to rutting research of sulphur-extended asphalt with various content of sulphur was performed using modern methods of rutting tests which imitate real conditions of a pavement functioning. It was found that the resistance of sulphur-extended asphalt to rutting is much higher than that of traditional asphaltic concretes. Moreover, increasing the sulphur content results in the increment of this indicator. It was found that the asphaltic concrete resistance to shear can not be truly defined by use of the methods of the existing GOST 12801-98.
DOI: 10.22227/1997-0935.2016.12.70-78
Pages 79-90
The authors consider main characteristics of modern development of renewable energy sources (RES). It is dedicated that there are some technical and economic barriers to the widespread use of renewable energy. For example, RES are inconstancy in time and space and have low density of energy flow. High capital intensity and cost price, long-term construction, a considerable degree of different kinds of risk, lack of competitiveness with hydrocarbon species generation in the existing regulatory environment are also inherent to RES. The role of the regulatory framework is shown according to perspective plans of construction of power plants using renewable energy sources. The main requirements which are applied to measures of state support of construction industry of renewable energy development are formulated. Current condition of construction industry of RES in Russia is assessed. The problems of risks which arise during construction of renewable energy facilities according to results of practical use of RES are discussed. And it is rather important to use stage assessment for the construction phase of the project during risk analysis of construction of alternative energy sources. The main groups of RES risks are described. The importance of regulatory and resource risks for effective development of renewable energy in Russia according to the method of strategic planning with the identification of the adverse effects of gradation factors are determined. The analysis of financial risks types and methods of its management during construction power generation projects based on different types of renewable energy resources are made. In the end of the article the authors make a conclusion, that the development of projects for the construction of power plants with the use of innovative technical solutions to ensure minimal risks to the environment and safe operation in various climatic conditions is a priority.
DOI: 10.22227/1997-0935.2016.12.79-90
Pages 91-102
Issues of environmental safety of tailings of ore mining and processing enterprises are considered; parameters of drainage of bund walls are of great significance for the environmental safety. Description of the bund wall of Mirny ore mining and processing enterprise and the tailings filling layouts are given. Results of field observation and model study of the tailings bund wall drainage system at Mirny ore mining and processing enterprise are presented. The drainage system rebuilding project analysis was performed. Proposals for its improvement were set forward.
DOI: 10.22227/1997-0935.2016.12.91-102
Pages 103-113
In general, the classification of bank protection structures of active and passive types with indication of advantages and disadvantages of each structure is illustrated. Factors having a destructive impact on bank protection structures are specified. Possible destructions of coatings thereof due to effects of waves and ice are considered. Necessity of the scientific monitoring of bank protection structures designing is rationalized.
DOI: 10.22227/1997-0935.2016.12.103-113
Pages 114-123
This article is dedicated generalization of the approach to the formation of the integral potential of organizational and technological solutions. The scheme of decomposition of the main elements of a construction project is presented. Considered and described in detail the research algorithm and the formation of the integral potential of organizational and technological solutions and components as single integral potentials. It is proposed to divide the studies into following phases: selection of the unit capacity to be considered through the construction project decomposition into elementary components; carrying out expert studies to identify key parameters that influence the performance of a single building; development of a mathematical model based on regression dependence; the use of mathematical models to improve the performance of the integrated construction project potential. Components of the “elements - construction project” system are in line with the basic provisions of systems engineering, which are its subsystem. It was selected groups of professional experts with experience and knowledge in their respective fields. As a rule, they are managers and chief engineers of construction companies participating in the polls as experts. The formation of a mathematical model of a single integrated potential is based on the assumption that the probabilistic nature of addiction, but a tool for its construction will be a multifactor regression built on the basis of probabilistic and statistical methods. The examples of the practical use of the new tools such as an integrated potential of organizational and technological solutions are considered. Having numerical characteristics of individual integrated potentials, one can create indexes and algorithms to form the integrated potential of organizational and technological solutions of the construction project.
DOI: 10.22227/1997-0935.2016.12.114-123
Pages 124-137
In the article, main moments of investigation of development of the investment construction complex as a subsystem of the national economy are presented. The urgency of investment construction complex research as a synergistic system with using a phased approach is substantiated to identify systemic patterns and modeling capabilities for the accelerated development due to the synergistic effects. Exploring statistic and directions of phase curves of main economic parameters of the investment-construction complex, it is found that the construction sector in 2011 came out to attractor which still tied with raw materials through the development of the economic system, so innovative development is possible through the bifurcation of the phase portrait caused by bifurcation of the Russian economy.
DOI: 10.22227/1997-0935.2016.12.124-137
Pages 138-146
The problems of relocation of citizens from unfit and slum dwellings are considered. Residential property market analysis illustrating a house construction attenuation was performed. The problems of provision of quality and equivalent housing are touched, and the reasons for inaccessibility thereof are illustrated. Measures taken for control of quality of the provided houses are considered. Attention is drawn to development problems of the North Caucasus as an example of one of the problematic regions. For the system solution of the erected housing quality issue it is planned to introduce this year the obligation for a self-regulatory organization to have a permit for design and construction of low-rise buildings. It is necessary to focus on the quality of housing, on elimination of corruption, improvement of work of the body for the housing stock price formation, and the local self-governing authorities. The carried-out measures with due attention of regions’ authorities will enable to keep priority rates of the unfit dwelling liquidation and fulfil the general tasks set by the President and the RF Government.
DOI: 10.22227/1997-0935.2016.12.138-146
Pages 147