INNOVATIVE APPROACHES TO EDUCATION OF FUTURE SPECIALISTS AND SCIENTISTS
Pages 5-6
Articles count - 16
Pages - 177
Pages 5-6
Pages 7-15
The authors consider the problems related to available environment formation in the strategy of touristic cities development. One of the means of social and psychological rehabilitation of the disabled is tourism. It should be noted, that touristic cities mostly represent a complicated space structure with a lot of streets and concourses, with touristic objects distributed all over the city. Visiting and transportation in such an environment may cause difficulties. The aim is to form a touristic universal environment. A universal environment is aimed at widening the frames of a design target group and supposes an organization of comfortable city visit, availability of services, simple and recognizable navigation system for all the social groups. The suggested principles may become a guidance not only to the designers. The given material may also be useful for specialists in territorial marketing and touristic management and help to raise a regional economic efficiency.
DOI: 10.22227/1997-0935.2015.9.7-15
Pages 16-27
Beginning with the 20th century metal structures are widely used in the construction branch in Russia. The reason for it was in the development of calculation methods of structures. Beginning with 1930 and till now a substantial number of the industrial buildings (about 90 %) of production plants have been built of metal structures. The essential part of them - 20…60 % of the whole volume - has block coverings consisting of bearing and braced elements. At the present time the data on the operation duration of industrial structures is not systemized throughout Russia. This data may serve as one of characteristic factors for estimating safety operation level, because while the operation term increases, the wear also increases (mechanical damages), which influences the bearing capacity of the structures. The following article examines the collapse of industrial building coverings that may be accompanied not only by material losses, but also by fatal accidents. Statistical data of damageability of trusses and their elements are presented; the consequences of collapse are examined. The average life time of trusses is determined which is serving as a criteria that characterizes damage accumulation. The nature of the collapse of block coverings is revealed which, in most cases, may be classified as progressive.
DOI: 10.22227/1997-0935.2015.9.16-27
Pages 28-35
Modern intensive development of precast-cast-in-place construction has led to creation of a wide range of various constructive systems of buildings during the last 100 years. They allow constructing buildings with best account of the requirements of functionality, architectural expressiveness, production possibilities of construction companies, etc. However in spite of this development both precast and cast-in-place housing construction has its peculiarities, positive and negative ones. The constructive systems of precast monolithic buildings existing at the moment are based on the required mutual deformation of prefabricated reinforced and cast iron reinforced concrete at the stage of a building construction and at the stage of its use as well. Having refused from this rule, the authors of this article have introduced a constructive system of a precast monolithic building able to bear loads, developing at the stage of erection (due to completion of a precast frame) and at the stage of use (due to completion of a precast monolithic frame). The offered construction of a precast monolithic building frame allows efficiently using the advantages of precast and cast-in-place construction minimizing their disadvantages and it also fully corresponds to the obligatory requirements to buildings. The corresponding patents are obtained.
DOI: 10.22227/1997-0935.2015.9.28-35
Pages 36-50
The behavior of reinforced concrete elements under some types of cyclic loads is described in the paper. The main aim of the investigations is research of the stress-strain state and strength of the inclined sections of reinforced concrete beam elements in conditions of systemic impact of constructive factors and the factor of external influence. To spotlight the problem of cyclic loadings three series of tests were conducted by the author. Firstly, the analysis of the tests showed that especially cyclic alternating loading reduces the bearing capacity of reinforced concrete beams and their crack resistance by 20 % due to the fatigue of concrete and reinforcement. Thus the change of load sign creates serious changes of stress-strain state of reinforced concrete beam elements. Low cycle loads of constant sign effect the behavior of the constructions not so adversely. Secondly, based on the experimental data mathematical models of elements’ strength were obtained. These models allow evaluating the impact of each factor on the output parameter not only separately, but also in interaction with each other. Furthermore, the material spotlighted by the author describes stress-strain state of the investigated elements, cracking mechanism, changes of deflection values, the influence of mode cyclic loading during the tests. Since the data on the subject are useful and important to building practice, the ultimate aim of the tests will be working out for improvement of nonlinear calculation models of span reinforced concrete constructions taking into account the impact of these loads, and also there will be the development of engineering calculation techniques of their strength, crack resistance and deformability.
DOI: 10.22227/1997-0935.2015.9.36-50
Pages 51-60
The supports of a overhead wiring used in transport take up substantial loads both because of wires and constructions holding them and wind, dynamic and other extraordinary impacts. In case of using single-member piles a question about their stability appears. For this reason different sleepers constructions are used. In order to improve the bearing capacity of horizontally loaded single pile supports of the contact systems used in urban, road and rail transport, power lines, etc.., it is recommended to use sleepers as horizontally laid under the ground in the depth of support beams. The calculation methods for different support sleepers of different lengths and cross sections are not well investigated. The proposed calculation method allows determining the carrying capacity of horizontally loaded bearings with soil pieces of different structural dimensions and their location in the soil, which allows choosing the best option for cost and material consumption. The calculations offered by the authors prove the efficiency of sleepers use in order to increase the bearing capacity of horizontally loaded piles and the possibility to chose their size.
DOI: 10.22227/1997-0935.2015.9.51-60
Pages 61-72
Natural non-treated sand reinforced with randomly oriented short polypropylene fibers of 12 mm in length was tested to determine creep characteristics. This study is a part of the research aimed at encouraging fibrosand (FRS) application in subsoils, embankments and retaining wall constructions. Fiber content was accounted for 0.93 %. Twin specimens were put to creep tests (1-D compression) using the two curve method. The test results were analyzed and checked with the use of ageing, hardening and hereditary creep theories. On the basis of approximation of the test results the creep deformation equation at constant stress for tested fibrosand was obtained. The assessment of fibrosand secondary compression was carried out by the FORE method. As a result, the value of the void ratio by the end of the secondary compression had been eu=0.7041. For determination of the beginning of the secondary compression the rate equation was superimposed on the empirical curve. The point of the graph divergence is the beginning of the secondary compression process. The secondary compression had begun by the time moment being equal to 9360 min. The void ratio by the beginning of the secondary compression had amounted to 0.70574. Fibrosand is a specific type of improved soil relating to so-called pseudo-cohesive soil. This type of soil is characterized by cohesion like cohesive soils, but, at the same time, by the filtration coefficient of about 1 m per day like non-cohesive soils. Pseudo-cohesive soil testing helps to understand the distinctive features of the stress-strain state of this kind of materials. Municipal solid waste also relates to them.
DOI: 10.22227/1997-0935.2015.9.61-72
Pages 72-83
The article presents the formulation and analytical solution to a quantification of stress strain state of a two-layer soil cylinder enclosing a long pile, interacting with the cap. The solution of the problem is considered for two cases: with and without account for the settlement of the heel and the underlying soil. In the first case, the article is offering equations for determining the stresses of pile’s body and the surrounding soil according to their hardness and the ratio of radiuses of the pile and the surrounding soil cylinder, as well as formulating for determining equivalent deformation modulus of the system “cap-pile-surrounding soil” (the system). Assessing the carrying capacity of the soil under pile’s heel is of great necessity. In the second case, the article is solving a second-order differential equation. We gave the formulas for determining the stresses of the pile at its top and heel, as well as the variation of stresses along the pile’s body. The article is also formulating for determining the settlement of the foundation cap and equivalent deformation modulus of the system. It is shown that, pushing the pile into underlying layer results in the reducing of equivalent modulus of the system.
DOI: 10.22227/1997-0935.2015.9.72-83
Pages 83-94
Erosion protection landscaping embedment of steep subsoil slopes is a time-sensitive issue of road construction and planning of recreational area that are often fit on a challenging picturesque terrain unsuitable for site development. The article provides the results of a 4-year experiment on landscaping and plant fixing of up to 4.5 m soil slopes with 1:1 and 2:1 grades; the experiment was carried out by the MGSU on the territory of a convent in the south of the Nizhniy Novgorod region. The site has slopes oriented towards all cardinals. At some places the slopes are bedimmed by trees. All these factors create a wide range of geo-ecological conditions for lawns. All the slopes are fixed with geo-fibrefill grids; slopes with 2:1 grade are strengthened by auxiliary grids made of reinforced metal bars, anchors and braces on the bottom of the Holy Moat. The paper recommends composition of grass plants as well as techniques to build up lawns suitable for various micro-climate conditions. It also advises the structure of multi-tier plant entity. The suggested methods are tested during a 3-year maintenance of slopes built for constant use.
DOI: 10.22227/1997-0935.2015.9.83-94
Pages 95-110
In 2011 in Russia a Strategy of Production Development of Construction Materials and Industrial Housing Construction for the period up to 2020 was approved as one of strategic documents in the sphere of construction. In the process of this strategy development all the needs of construction complex were taken into account in all the spheres of economy, including transport system. The strategy also underlined, that the construction industry is a great basis for use and application in secondary economic turnover of dangerous waste from different production branches. This gives possibility to produce construction products of recycled materials and at the same time to solve the problem of environmental protection. The article considers and analyzes scientific methodological approaches to creation of a model of a complex control system for the streams of building waste in frames of organizing uniform ecologically safe and economically effective complex system of waste treatment in country regions.
DOI: 10.22227/1997-0935.2015.9.95-110
Pages 111-121
Hydraulic turbine suction pipes at hydropower plants (HPPs) play an important role for providing high power indices of HPP operation. At the same time for channel type HPPs with vertical reactive hydraulic turbines curved large size suction tubes are used and this leads to great costs for their installation. That is why the significance of economic analysis for justification of the size of such suction pipes is underlined. Minimally possible sizes of curved pipes (height and length) are determined by hydraulic turbine normal operation requirements and are given in reference books. Nevertheless often such conditions arise when the correction of their size leading to their enlargement becomes inevitable. In particular, when there are rocks at a small depth below of the project position of the foundation slab it is feasible to increase a suction pipe’s height to place the foundation concrete on the strong rock. Or if it is necessary to make a motorway at the downstream side of a channel HPP lengthening of a suction pipe appears sensible. In such cases economic calculations are necessary on feasibility of suction pipe size change proposals. The use of an integral effect technique for such an analysis is proposed. The article provides a criterion for economic efficiency of the given technique. In conformity with it the calculations for a hydraulic turbine with 9 m diameter under acting head of 24 m are made. The calculation results are presented as graphs of dependencies of integral effect on varying parameters. The analysis of the results shows that a parameter being changed (suction pipe lengthening) has a distinct optimal value, which in the investigated variants is 2.5...3.0 m. Herewith a maximal value of economically justified hydrogenerator suction pipe lengthening satisfying the criterion adopted is in the range of 7.5...8.0 m. It is also shown that the value of the integral effect depends significantly on electric energy tariffs and the conditions of HPP operation.
DOI: 10.22227/1997-0935.2015.9.111-121
Pages 122-129
The article describes the active equilibrium motion of bed forms, which occurs in rivers during high water periods. The authors consider the relation between an average size of the particles of which little bed-forms (rifles) are formed and an average size of non-cohesive material in case of which armoring is formed in a river. These particles have a diameter of 0.5…0.6 mm. This boundary is associated with different mechanisms of stability loss for smaller particles, for which the probability of weighing is greater than for the larger particles. The article offers the extrapolation of the dependence of the ratio of average speed to critical speed received by V.N. Goncharov at small depths (up to 0.2 m) at the depth of 5 m on the basis of the experiments presented by V. Rijn. It is shown that the ratio of the dynamic speed to its critical value decreases with the increase in the size of alluvial particles, for bed formation and wash moments. For the moments of bed formation reaching the maximum bed height (maximum resistance in the channel) and erosion of the bed-forms was well confirmed by the values of the dimensionless parameter (the ratio of average velocity to hydraulic size taking into account the flow regime) for a particle size of about 1 mm.
DOI: 10.22227/1997-0935.2015.9.122-129
Pages 130-145
The modern transport system is a complex integrated object, which includes various road pavements, different technical means to provide vehicles motion, organizational systems of traffic management. In the contemporary conditions of construction industry functioning the task to create vehicle systems is of a great economic importance. Great labour and material resources are used for production of transport means for providing construction works and operation of these means. The authors consider the questions of theoretical and informational foundation development for the formation of the criteria basis of investment optimization task during construction of automatical and informational systems for increase of traffic safety in transport systems, providing zero accident rate.
DOI: 10.22227/1997-0935.2015.9.130-145
Pages 146-157
The starting stage of the tender procedures in Russia with the participation of foreign suppliers dictates the feasibility of the developments for economical methods directed to comparison of technical solutions on the construction field. The article describes the example of practical Life Cycle Cost (LCC) evaluations under respect of Present Value (PV) determination. These create a possibility for investor to estimate long-term projects (indicated as 25 years) as commercially profitable, taking into account inflation rate, interest rate, real discount rate (indicated as 5 %). For economic analysis air-blower station of WWTP was selected as a significant energy consumer. Technical variants for the comparison of blower types are: 1 - multistage without control, 2 - multistage with VFD control, 3 - single stage double vane control. The result of LCC estimation shows the last variant as most attractive or cost-effective for investments with economy of 17,2 % (variant 1) and 21,0 % (variant 2) under adopted duty conditions and evaluations of capital costs (Cic + Cin) with annual expenditure related (Ce+Co+Cm). The adopted duty conditions include daily and seasonal fluctuations of air flow. This was the reason for the adopted energy consumption as, kW∙h: 2158 (variant 1),1743...2201 (variant 2), 1058...1951 (variant 3). The article refers to Europump guide tables in order to simplify sophisticated factors search (Cp /Cn, df), which can be useful for economical analyses in Russia. Example of evaluations connected with energy-efficient solutions is given, but this reference involves the use of materials for the cases with resource savings, such as all types of fuel. In conclusion follows the assent to use LCC indicator jointly with the method of determining discounted cash flows, that will satisfy the investor’s need for interest source due to technical and economical comparisons.
DOI: 10.22227/1997-0935.2015.9.146-157
Pages 158-167
Planning and implementation of innovations on the microlevel of management and on the higher levels is a process of innovative projects portfolio implementation. Project management is aimed at some goal; therefore, defining the mission and aims of implementation is of primary importance. These are the part of the notion of development strategy of an enterprise. Creating a strategy for big construction holding companies is complicated by the necessity to account for different factors effecting each business-block and subsidiary companies. The authors specify an algorithm of development and implementation of the activity strategy of a big construction enterprise. A special importance of the correspondence of organizational management structure to the implemented strategy is shown. The innovative character of organizational structure change is justified. The authors offer methods to optimize the organizational management structure based on communication approach with the use of the elements graph theory. The offered methodological provisions are tested on the example of the Russian JSC “RZhDstroy”.
DOI: 10.22227/1997-0935.2015.9.158-167
Pages 168-177
The authors present the main properties of the planar configuration of Desargues, which open the possibility of its widespread use in architectural design and the design of complex volumes, consisting of a series of simple overlapping forms. However, the computer implementation of Desargues configuration construction is associated with certain difficulties caused by the fact that the monitor can only discretely represent the graphical information. In this article we identified and analyzed the properties of Desargues configuration, the use of which allows overcoming these difficulties and solving the problem of the limited capacity of monitors in the development of complex architectural forms with the help of computer graphics. Along with this, the use of the allocated properties allows predicting complex effects of the perception of architectural forms, for example, the difference of perception of architectural objects near and afar with account for perspective distortion, and they are also the basis for the development of the algorithm of construction sequence during design.
DOI: 10.22227/1997-0935.2015.9.168-177