scholarly journals TECHNICAL CONDITION OF CORRUGATED METAL TRANSPORT STRUCTURES

Author(s):  
J. J. LUCHKO ◽  
V. V. KOVALCHUK

Purpose. The purpose of the work is to establish the real technical condition of transport structures made of corrugated metal structures on the basis of the analysis of scientific and technical sources.And to analyze the experience of operation of metal corrugated structures in the soil environment and to form and generalize the problems of ensuring the reliability and durability of structures made of metal corrugated structures in the conditions of operation on railways and highways of Ukraine. Methodology. To achieve this goal, a review of scientific and technical sources and regulations of different countries on the technical condition of transport facilities in Ukraine was conducted. In particular, data on the distribution of bridges and pipes made of corrugated metal structures by mode of transport are given. It is shown that the development and implementation of new technologies for the repair of existing defective pipes and small bridges, both on the railways and highways of Ukraine is a very important issue. A thorough analysis of the experience of operation of corrugated metal structures in the soil environment in different countries was conducted. Data on the main inadmissible defects of pipes and the reasons of their development are given. CMS' (corrugated metal structures) corrosion and other defects are given. A number of examples of overpass defects, collapse of bridges and structures with MCS in operation are presented. The qualitative indicators of metal corrugated structures, their advantages and disadvantages are also considered, the problems and the analysis of ensuring the reliability and durability of the structures with CMS in the conditions of operation on the railways and highways of Ukraine are formulated. Findings. An analysis of domestic and foreign scientific and technical sources on the technical condition of transport facilities in Ukraine was conducted. In particular, the experience of operation of corrugated metal structures in different countries of the world is studied and generalized. The analysis and synthesis of problems of ensuring the reliability and durability of buildings with CMS in the conditions of operation on the railways and highways of Ukraine. Originality. As a result of the analysis of the technical condition of transport facilities operated on railways and highways of Ukraine, it was found that about 15 % of transport facilities – small and medium bridges and culverts on Ukrainian railways and about 45 % of transport facilities on Ukrainian roads have unacceptable defects and require immediate repair and replacement. Also, it was established on the basis of research that there are no methods for assessing the load-bearing capacity of transport facilities with CMS in the presence in the body of the embankment of the railway or highway metal corrugated structures with a diameter greater than 6 m. It was determined that standards don't include regulations on design and monitoring of CMS on railway tracks. Practical value. On the basis of these data it was possible to offer directions of theoretical and experimental research and methods of calculation, tests of CMS and diagnostics of a technical condition of transport structures with CMS. In particular, the measurement of the impact of the environment on the bearing capacity of the CMS and the measurement of residual deformations of the corrugated metal pipe on the railway track. Execution of the analysis and synthesis of methods of calculation of transport constructions with CMS will lead to improvement of methods of calculation of CMS.

2021 ◽  
Vol 16 (2) ◽  
pp. 90-109
Author(s):  
Vitalii Kovalchuk ◽  
Mykola Sysyn ◽  
Yuriy Hnativ ◽  
Artur Onyshchenko ◽  
Maksym Koval ◽  
...  

The paper deals with damages of transport constructions made of corrugated metal structures in the body of a railway track or a road during their operation. A constructive variant to restore the bearing capacity of structures was developed, which consists of installing an annular stiffening rib into the concave part of the corrugated metal profile. The main advantage of this method compared to the double corrugating method is the possibility of performing the reinforcement works during structure operation without interrupting the movement of transport vesicles. The study has proved that the reinforcement method significantly increases the carrying capacity of corrugated metal structures. A numerical finite element model was developed to determine the stress-strain state of structures made of corrugated metal structures reinforced with round stiffening ribs. The soil pressure on the corrugated shell in the model is taken into account with the application of radial and axial forces on the outer surface of the shell. It was determined that the most appropriate location of the ribs is in the centre of the building, where the reinforcement area corresponds to the width of the road or railway line. The advantage of this approach is the ability to more efficiently distribute the reinforcement material by selecting the ribs in the most loaded sections of corrugated metal structures.


2011 ◽  
Vol 3 (2) ◽  
pp. 64-71 ◽  
Author(s):  
Kęstutis Kelevišius ◽  
Jonas Amšiejus ◽  
Šarūnas Skuodis

In most cases, the bearing capacity of the pile under natural conditions can be determined by applying static and dynamic pile tests as well as the numerical modelling of a dynamic test. The integrated business problem is employed for calculating vertical displacements. This integral is calculated using the summing method. In the majority of cases, real pile strength capacity can be investigated referring to the adapted means of testing applying the mathematical model that can calculate static or dynamic investigations. The idealized scheme of a pile test is presented including a hammering system and soil properties. Moreover, information on the analysis and work of the scheme is disclosed. The article also describes pile hammering models and the equation for Smith method improved by Edwards, Holloway, Briaud and Trucker, Rieke and Crowser, ”GRL“, including the advantages and disadvantages of the introduced method. Smith realized the mathematical analysis of wave propagation supported by a real hammer-pile-soil scheme by discretic elements interaction. Basing on this for classical one dimensional method of wave propagation (that is programmed in computer program MW87) the code of the computer program was changed by authors of this article. When using a computer program, an algorithm for an integral equation was created. The introduced algorithm was made for counting experimental displacement the growth of which along the pile was analyzed. All obtained results were compared with the engineering method indicating that diff erence in results made less than 2%. Using computer program MW87, a diff erent distribution of shaft friction along the pile was studied when the total shaft friction in all cases was constant, because, the results of numerical modelling disclosed that the shaft friction of the pile in one diameter above the pile’s toe was larger than that in the middle or at the top. The hammer-pile-soil system was analyzed with reference to the impact of the returning wave at the top of the pile. Wave propagation in the pile is vertical: the first wave moves from the top to the bottom of the pile. When the bottom is reached, impact wave returns to the top of the pile. All information about the pile of the returning wave is useful as then we can analyze the integrity and bearing capacity of the pile. All this information received from the returning wave is integrated and later shown in the scheme where we can see all steps of performed operations. This article investigates soil deformations and these deformations in soil influence for a hammering pile. A pile of 0,8 m in diameter and 3 m in height, which is in sand, is an object of investigation in this article. For calculation purposes, the pile is divided into 20 segments. Changes in velocities and displacements of pile segments during analysis are graphically shown. Aft er calculating tests on pile dynamics considering diff erent masses of hammers, falling heights of hammers, contribution of shaft friction and static resistances of the piles, a nomograme for determining static resistance of the pile was made. The article explains how the use of the nomograme determines static resistance of the pile and what data on conducting a pile test are needed.


Author(s):  
Iryna Rudnieva

Built mostly centuries ago, heritage buildings as well the more contemporary buildings of the last century, which have lost the bearing capacity often need restoration and strengthening, especially in seismic regions and in regions with shrinkage phenomena (subsidence region). The need of strengthening of the building constructions during exploitation appears mostly because of their premature wear as a result of technological influences and weathering, various damage and various other factors. Traditional methods of strengthening are effective, but in some cases not appropriate or not applicable  for use. An example is the increase of the load-bearing structures of historical buildings, preserving the external appearance of which is the determining factor. In this case, the use of the discussed alternative methods can be justified alternative. Knowledge of the causes of defects and damage of structures allows to choose the best option of repairing or strengthening. The aim of the research is the evaluation of the structural performance of composite fibre-reinforced elements in the wider sector of the conservation of historical, architectonic and environmental heritage, as well the more contemporary buildings of the last century, which have lost of the bearing capacity focusing reliability indexes and the appearance of the structure. In the article was described and analyzed the existing traditional methods and the alternative methods of strengthening by FRP-materials (composite materials) such building structures as masonry, metal structures, reinforced concrete, and the computation in software ABAQUS. These procedures of strengthening building structures by FRP-materials  in Ukraine are not widely used due to the lack of a regulatory framework that would regulate their use, as well because these materials are relatively expensive compared to the traditional ones. The article analyzed the existing methods of computation and design of the strengthening using FRP-materials, and the computation in software ABAQUS was performed with conclusions and recommendations based on results of the computation. The aim of the work was to review the technology and analyze the advantages and disadvantages of each of the strengthen methods that should be used when choosing effective solutions for strengthening building structures. In conclusion, the need for further study and researches was confirmed.


2021 ◽  
Vol 100 (1) ◽  
pp. 13-18
Author(s):  
Svetlana P. Babenko ◽  
Andrey V. Bad’in

Introduction. This article refers to the authors’ calculation method for studying the effects UF6 (uranium hexafluoride, UHF) on the human body. A review of this method’s main ideas and the features of the approach to solving the problem at certain stages of the movement of UHF from being released into the air before entering the body is offered. The possibilities of the proposed method and its place in many well-known studies in this direction are described. Material and methods. The research material is UHF. It serves as the primary working substance in technologies for enriching natural uranium with the 235U isotope. UHF, due to various circumstances, appears in the production room in a gaseous state. A method for studying the effects of UHF on humans is to describe the distribution processes of UHF molecules in the volume of the working room, chemical transformations of UHF, physical transformations of the resulting products, i.e., all processes accompanied by the delivery of toxic substances and their transfer from the source to the person and before excretion from the body in a natural way. The description of these processes is carried out analytically. Results. Lists the results that can be obtained by calculation. Discussion. A discussion of the results is carried out in the following areas. The issue of the possibility of using the described calculation method to solve the problems of ensuring labor safety at work is considered. The question of trust in the calculated values characterizing the effect of UHF on the human body is being studied. To solve this problem, we compared the calculated results obtained for a particular process and the experimental ones implemented in a similar process. Conclusion. A conclusion is made regarding the advantages and disadvantages of the method under investigation for studying the effects of UHF on humans and determining their place among existing methods.


Author(s):  
J. LUCHKO ◽  
Y. KOVALCHUK ◽  
I. KRAVETS

Purpose. The aim of the research is to analyze the methods of calculating and evaluation of  the bearing capacity of corrugated metal structures (the CMS) in cooperation with  soil backfill as a result of stress from rolling stock or vehicles.  To prove the applicability of these methods for the calculation of pipes of different diameters and different structural forms. Methodology. The methods of calculating the deflected mode of corrugated metal pipes of small diameter (up to 3 m.) at constant load, and calculation methods CMS of large diameter more than 6 m are analyzed. Findings. The calculated models that take into account the spatial work of structures is more correct than " flat " models and calculated scheme, and therefore the calculation of the CMS is to apply three-dimensional calculation model which model the most realistic work of corrugated metal structures. Originality. For the first time the methods of calculation and experience designing of flexible corrugated metal structures at interaction of soil backfill and under the influence of the stress from the rolling stock and road transport are analyzed. Practical value. The obtained analysis of the evaluation methodologies of the bearing capacity of corrugated metal structures of different shape section can be used by engineers in bridge probationary stations Ukrainian Railroad (UR) and Ukravtodor and project organizations involved in the design and construction of the CMS.


Author(s):  
Ziyi Chen ◽  
Aiping Wu

Abstract Tissue immune cells have long been recognized as important regulators for the maintenance of balance in the body system. Quantification of the abundance of different immune cells will provide enhanced understanding of the correlation between immune cells and normal or abnormal situations. Currently, computational methods to predict tissue immune cell compositions from bulk transcriptomes have been largely developed. Therefore, summarizing the advantages and disadvantages is appropriate. In addition, an examination of the challenges and possible solutions for these computational models will assist the development of this field. The common hypothesis of these models is that the expression of signature genes for immune cell types might represent the proportion of immune cells that contribute to the tissue transcriptome. In general, we grouped all reported tools into three groups, including reference-free, reference-based scoring and reference-based deconvolution methods. In this review, a summary of all the currently reported computational immune cell quantification tools and their applications, limitations, and perspectives are presented. Furthermore, some critical problems are found that have limited the performance and application of these models, including inadequate immune cell type, the collinearity problem, the impact of the tissue environment on the immune cell expression level, and the deficiency of standard datasets for model validation. To address these issues, tissue specific training datasets that include all known immune cells, a hierarchical computational framework, and benchmark datasets including both tissue expression profiles and the abundances of all the immune cells are proposed to further promote the development of this field.


2018 ◽  
Vol 15 (2) ◽  
pp. 1-20
Author(s):  
Sabri Embi ◽  
Zurina Shafii

The purpose of this study is to examine the impact of Shariah governance and corporate governance (CG) on the risk management practices (RMPs) of local Islamic banks and foreign Islamic banks operating in Malaysia. The Shariah governance comprises the Shariah review (SR) and Shariah audit (SA) variables. The study also evaluates the level of RMPs, CG, SR, and SA between these two type of banks. With the aid of SPSS version 20, the items for RMPs, CG, SR, and SA were subjected to principal component analysis (PCA). From the PCA, one component or factor was extracted each for the CG, SR, and RMPs while another two factors were extracted for the SA. Primary data was collected using a self-administered survey questionnaire. The questionnaire covers four aspects ; CG, SR, SA, and RMPs. The data received from the 300 usable questionnaires were subjected to correlation and regression analyses as well as an independent t-test. The result of correlation analysis shows that all the four variables have large positive correlations with each other indicating a strong and significant relationship between them. From the regression analysis undertaken, CG, SR, and SA together explained 52.3 percent of the RMPs and CG emerged as the most influential variable that impacts the RMPs. The independent t-test carried out shows that there were significant differences in the CG and SA between the local and foreign Islamic banks. However, there were no significant differences between the two types of the bank in relation to SR and RMPs. The study has contributed to the body of knowledge and is beneficial to academicians, industry players, regulators, and other stakeholders.


2020 ◽  
pp. 15-18
Author(s):  
Inna R. Kilmetova ◽  
◽  
Igor A. Rodin ◽  
Nazira I. Khayrullina ◽  
Nikolay G. Fenchenko ◽  
...  

Summary. The disbalanced feeding and the uneven distribution of micro- and macroelements in the environment leads to a trace element, in particular hypomelanosis. To accelerate the growth and preservation of young farm animals include in the diet of various biological additives and drugs, which include selenium. For stimulation of weight gain in the livestock industry, as well as for the prevention and treatment of pathological processes in addition to micro - and macrouse amino acids, primarily methionine. The aim of this work was to study the influence of composition of DAFS-25+Polizon on morpho-biochemical parameters of blood and functional state of the liver in fattening bulls of black-motley breed in the conditions of the Republic of Bashkortostan. Experiments using were conducted on bull-calves of black-motley breed of the properties in the properties age from 6 to 15 months. The first experimental group during the experiment was additionally given the composition of DAFS-25+Polizon at a dose of 2 mg/kg, the animals of the control group received a standard diet. To assess the impact of the composition DAFS-25+Polizon on metabolism cattle studied morphological and biochemical indicators of blood and conducted histological examination of the liver. It is established that the use of the composition of DAFS-25+Polizon at a dose of 2 mg/kg increases the number of erythrocytes and hemoglobin in the experimental group and reduces the amount of white blood cells. The serum content of total protein, phosphorus and calcium increases in the group of experimental animals. Microscopic examination of the liver revealed no changes in the structure of the organ and hepatocytes in the experimental group, whereas in the control group hemodynamic disorders and dystrophic changes in liver cells were observed. Thus, the use of the composition DAFS-25+Polizon at a dose of 2 mg/kg of live weight in fattening bulls black-and-white breed contributes to the increase of redox processes in the body, stimulation of metabolism, prevent the development of liver disorders of cellular mechanisms of metabolism, optimizes the structure of the liver, which generally provides higher productivity.


Author(s):  
Gintarė VAZNONIENĖ ◽  
Bernardas VAZNONIS

In this article the significance of wellbeing research in the regional level in Lithuania has been analyzed, the advantages and disadvantages of the objective and subjective wellbeing research have been evaluated. The results of the analysis of wellbeing research reveal that the wellbeing research in the regional level is poorly amplified, the wellbeing research in the social sciences is not marked, the wellbeing is investigated in other fields not in social sciences or according to the aims of the researher and more often causes and outcomes of social economical inequality for regional development are emphasized. Scientific studies show that wellbeing research can have big influence for shaping the future of regions because it concerns local people, their choices and overall wellbeing of a particular region. Findings from foreign countries good practice disclose that wellbeing is currently widely used as a key factor and trend for the development policy evaluation. Accordingly in this article big attention is drawn to wellbeing research possible effect for policymakers. It can be concluded that wellbeing research should become an important discussion object in the regional development context because it reveals the situation about people overall wellbeing and particular life domains. The main aim of this article is to analyse the importance of wellbeing research to regional level in Lithuania. The research problem of this article is the fact that the poor experience of wellbeing research in Lithuania insufficiently reveals the wellbeing expression and use in the regional level. In the research common research methods like analysis and synthesis of the scientific literature, analysis of documents and comparative analysis have been employed.


2020 ◽  
Vol 19 (10) ◽  
pp. 1896-1915
Author(s):  
E.R. Ermakova ◽  
O.M. Lizina

Subject. The article addresses the specifics of shadow economic activities in reformed Russia in the context of systemic transformations. Objectives. We focus on determining the role of shadow economy in the reproductive process, identifying and understanding the specifics of underground economic activity of the Russian economy. Methods. The study rests on general scientific methods (scientific abstraction, unity of historical and logical, analysis and synthesis, induction and deduction, comparison and analogy) and special methods of cognition (monetary methods). We employ the systems and integrated approach. The official statistics, regulations, works of leading researchers on shadow economy expansion, resources of reference and legal systems like Garant and ConsultantPlus serve as the study's information base. Results. We present a retrospective rapid analysis of the extent of shadow economic activity in the domestic economy, establishing the relationships with the processes that take place at different stages of the country's development. We also reveal the specifics of shadow economy relations in Russia, factors that play a key role in expansion for a particular period, a shift to another form of shadow economy. The study characterizes the current period of development, assesses the impact of external shocks on shadow economy expansion. Conclusions. The current period is characterized by the digitization of shadow relations, the shift of corruption to the upper echelons of power, the continued outflow of capital abroad, and increased penalties for underground activities.


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