dynamic of structures, bridges, finite element method
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Dynamic analysis of a cable-stayed bridge in Płock (Solidarity Bridge) has been considered. Finite element model was used in the frame of the SOFISTIK Programme. Free vibration modes are calculated as a base for the analysis. Dynamic transient analysis was done by the Newmark method as well as the method of modal superposition. The two methods have been compared from the point of view of the cost of analysis. Conditions of the successful use of modal superposition were defined.
ESTIMATION OF UNCERTAINTY OF STRENGTH FOR CUBICAL SAMPLES CONCRETE
Autor
Mariusz Sobolewski
Pages
17–28
Keywords
strength of concrete, uncertainty of result, estimation of strength, criteria of conformity, class of concrete, class of strength
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In constructional practice there is a must to verify: strength of designed concrete, quality control of industrial produced concrete and quality control of prefabricated elements during production. The next topic is estimation of strength concrete used in structure diagnostics. Evaluation of measurement result coming from contemporary metrology is another than in traditional statistical analysis. The theory of uncertainty applied now is based on probabilistic estimation sources of uncertainty related to investigation of measurand. This paper contains an analysis of calculation procedure for uncertainty of results and medium strength for cubical samples concrete. The results of laboratory strength fcmand their uncertainty are presented. Expression of uncertainty in measurements gives possibility to compare test results obtained from different laboratory on the higher level.
This paper concerns evaluation of initial stiffness in natural cohesive soils. Initial stiffness is here represented by the small strain shear modulus (G0), which was measured for the variety of the confining pressures and the mean effective stresses. The researches were conducted in laboratory, using the resonant column (RC) technique. The soil was isotropically consolidated and subsequently stiffness parameter was determined for each effective stress level. Different values of G0were evaluated, depending on the test conditions, then summarized on the general graphs. This study demonstrates as well conclusively high non-linear stress – strain behaviour of an examined material. The principal motivation of the article was improvement of our understanding of the stiffness property of natural soils at small strains.
LABORATORY TESTS OF WATER PERMEABILITY UNDER LOAD OF NON-WOVEN GEOTEXTILE EXPLOITED AT LANDFILL SITE
Autor
Eugeniusz Koda, Piotr Osiński, Sylwia Stępień
Pages
41–50
Keywords
non-woven geotextile, load, clogging, water permeability
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The non-woven geotextile is a commonly used material as a component fulfilling drainage systems especially on sites such as municipal waste landfills. The main advantage of geofilters is they help minimizing a clogging effect of drainage. The parameter that determinates the application usability of this product is water permeability. The paper present the research methodology and results analyses obtained from laboratory measurements for pure and exploited non-woven geotextiles under loads. The aim of the research was to determinate water permeability under differ exploitation and loading conditions. The measurements were conducted according to national standards. The results obtained allowed assessment of water permeability changes of tested material in time and under loads, and also allowed verification of the effectiveness of applied geofilters which were collected from the old municipal solid waste landfill.
DIFFUSION RN222 THE POLIETYN FOIL STRUCTURAL BARRIER
Autor
Marek Dohojda
Pages
51–57
Keywords
radon, diffusion, emission, exhalation
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The article discusses the problem of diffusion of radon in the soil, in particular, the penetration into the pores of open land. Also shows the path of migration of radon into buildings and the conditions that favor it. Given the resulting risks proposed technical measures to avoid the use of HDPE to prevent. Presents a method that allows the measurement of radon diffusion through polyethylene films.
REASONS FOR COMING INTO EXISTENCE OF THE MOISTURE OF OUTSIDE BARRIERS ON THE EXAMPLE OF THE RESIDENTIAL BUILDING IN WARSAW
Autor
Marek Dohojda, Krzysztof Wiśniewski
Pages
59–67
Keywords
thermal bridge, moisture of barriers
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The article discusses the causes of divisions in construction and moisture factors that favor the emergence of this phenomenon. Describes the methods of testing structural components that are exposed to moisture. Discusses the influence of thermal bridge on the formation of space and external partitions in buildings.
INFLUENCE OF THE MODERNIZATION OF BUILDINGS OF DAIRY COWS ON THEIR FUNCTIONALITY ON THE EXAMPLE OF THE BARN OF DAIRY COWS IN SGGW FARM OBORY-GOŹDZIE
Autor
Piotr Fornalczyk, Krzysztof Wiśniewski
Pages
69–76
Keywords
Keywords: modernization, cattle, dairy cows, technology, construction
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The paper presents ways to modernize dairy barns in terms of technology and construction. As an example of the technological modernization and construction work is shown to have been made in one of the barns at the farm located on the farm cows Cowshed experimental SGGW Obory-Goździe. The modernization consisted barn, changing technology, animal welfare and relevant changes in construction-construction for the purpose of the building.