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Number of results: 13
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Abstract

This paper presents the study of the impact of vibration induced by the movement of the railway rolling stock on the Forum Gdańsk structure. This object is currently under construction and is located over the railway tracks in the vicinity of the Gdańsk Główny and Gdańsk Śródmieście railway stations. The analysis covers the influence of vibrations on the structure itself and on the people within. The in situ measurements on existing parts of the structure allow us to determine environmental excitations used for validation and verification of the derived FEM model. The numerical calculations made the estimates of the vibration amplitudes propagating throughout the whole structure possible.
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Abstract

W twórczości projektowo-badawczej Wacława Zalewskiego znajduje się zrealizowana w 1965 konstrukcja eksperymentalna sprężonej powłoki betonowej wiszącej na heksagonalnym układzie łuków stalowych. Ze względu na ówczesny brak odpowiednich narzędzi badawczych oraz projektowych, ta skomplikowana statycznie i technologicznie budowla powstała w sposób doświadczalny na podstawie założeń koncepcyjnych Zalewskiego, który jednocześnie sprawował nadzór nad jej realizacją. Dynamiczne działania techniczne podczas realizacji konstrukcji mogą być klasyfikowane jako wczesne przejawy rozwiniętego w ostatnich latach poszukiwania formy obiektu architektonicznego określanego mianem ”form finding”. Przeanalizowanie założeń technicznych oraz technologii wznoszenia tego interesującego obiektu stanowią cel niniejszego artykułu. Ze względu na brak dostępnej dokumentacji autor opierał się na informacjach zebranych podczas rozmów z Wacławem Zalewskim i uzyskanych od niego fotografiach z realizacji obiektu.
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Abstract

Numerical analysis of the tensioning cables anchorage zone of a bridge superstructure is presented in this paper. It aims to identify why severe concrete cracking occurs during the tensioning process in the vicinity of anchor heads. In order to simulate the tensioning, among others, a so-called local numerical model of a section of the bridge superstructure was created in the Abaqus Finite Element Method (FEM) environment. The model contains all the important elements of the analyzed section of the concrete bridge superstructure, namely concrete, reinforcement and the anchoring system. FEM analyses are performed with the inclusion of both material and geometric nonlinearities. Concrete Damage Plasticity (CDP) constitutive relation from Abaqus is used to describe nonlinear concrete behaviour, which enables analysis of concrete damage and crack propagation. These numerical FEM results are then compared with actual crack patterns, which have been spotted and inventoried at the bridge construction site.
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Abstract

Accommodation tourist industry is characterized by high variability. For this category of services not only the location is crucial- that does not change, but also the standard, prices and seasonality of services. In the recent years, leisure centers performing functions only during the summer time have seen the possibility to extend their activities beyond the summer months. The reasons for this are the local investments requiring qualified staff which comes from different parts of the country, Europe and the world while creating dernand for accommodations. To meet the possible demand needs and to adapt to cold season, performing thermo-modernization works is necessary. In order to find the best solution and answer those needs, analysis of the profitability of the investrnents in a chosen holiday resort was carried out. The article presents the results of the analysis based on the payback period, LCC analysis and assessment of the investments risk.
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Abstract

Przestrzenne konstrukcje prętowe nazywane często strukturami przestrzennymi znalazły szerokie zastosowanie w świecie, szczególnie zaś w przekryciach obiektów o dużych rozpiętościach. Projektowanie obiektów w których znajdują zastosowanie prętowe struktury przestrzenne o skomplikowanej geometrii jej często poprzedzane licznymi badaniami teoretycznymi i modelowymi. Jednym z etapów projektowania, istotnym z punktu widzenia optymalizacji geometrycznej struktury jest wybór odpowiedniej metody wyznaczania jej morfologii. Opisując zjawiska zachodzące w naturze oraz sposób ich adaptacji do procesu projektowania architektoniczno-konstrukcyjnego autor przedstawia wyniki zastosowania metody analogii potencjałów energetycznych. Inspirację opracowania tej metody stanowi prawo Coulomba - przyjmując, że węzły dowolnej siatki przestrzennej są ładunkami elektrycznymi o ściśle określonych wartościach można otrzymać układ geometryczny w którym wszystkie elementy wzajemnie na siebie oddziałują. Ładunki przyjmą pozycje w przestrzenni dla których suma wzajemnych oddziaływań między nimi będzie najmniejsza. Będzie to układ najkorzystniejszy energetycznie. W niniejszej pracy przedstawiono rezultaty optymalizacji wykonanych z pomocą modeli i symulacji cyfrowych opracowanych przez autora, poddanych następnie uproszczonym analizom statycznym. Wyniki pokazano za pomocą zaproponowanych przez autora wskaźników efektywności.
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Abstract

Risks pertaining to construction work relate to situations in which various events may randomly change the duration and cost of the project or worsen its quality. Because of possible significant changes of random events, favorable, moderate, and difficult conditions of construction work are considered. It is the first stage of the construction risk analysis. The probabilistic parameters of construction are identified and described by using the design characteristics model of the structure and the construction technology model. The first describes the probabilistic properties of the structure execution's technology. The second describes the probabilistic properties of the works execution. Both models contain basic probabilistic data for scheduling, cost estimating, and risk assessment of the construction.
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Abstract

The subject of the analytical and experimental studies therein is of two metal seven-layer beam - plate bands. The first beam - plate band is composed of a lengthwise trapezoidally corrugated main core and two crosswise trapezoidally corrugated cores of faces. The second beam - plate band is composed of a crosswise trapezoidally corrugated main core and two lengthwise trapezoidally corrugated cores offaces. The hypotheses of deformation of a normal to the middle surface of the beams after bending are formulated. Equations of equilibrium are derived based on the theorem of minimum total potential energy. Three-point bending of the simply supported beams is theoretically and experimentally studied. The deflections of the two beams are determined with two methods, compared and presented.
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Abstract

Statistical conformity criteria for the compressive strength of concrete are a matter of debate. The criteria can have prejudicial effects on construction quality and reliability. Hence, the usefulness of statistical criteria for the small sample size n = 3 is questioned. These defects can cause a reduction in the quality of produced concrete and, consequently, too much risk for the recipient (investor). For this reason, the influence of conformity control on the value of the reliability index of concrete and reinforced concrete has been determined. The authors limited their consideration to the recommended standards PN-EN 206-1, PN-EN 1992 and ISO 2394 method of reliability index, which belongs to the analytical methods FORM (First Order Reliability Method). It assumes that the random variables are defined by two parameters of the normal distribution or an equivalent normal: the mean and the standard deviation. The impact of conformity control for n = 3 for concrete structures, designed according to the Eurocode 1992, for which the compressive strength of concrete is the capacity dominant parameter (sensitivity factor of dominating resistance parameter according to the FORM is 0.8), has been determined by evaluation of the reliability index.
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Abstract

W artykule został opisany most przez Wisłę o dwóch przęsłach rozpiętości 180 stóp angielskich (54,86 metra), zbudowany w połowie XVII wieku w Toruniu na terytorium Rzeczypospolitej Obojga Narodów. Przedstawiono wyniki badań źródeł numizmatycznych i ikonograficznych, a także planów miasta i źródeł pisanych. Badania wykazały, że konstrukcja toruńskiego mostu była wykonana z drewna w oparciu o koncepcję belki kratownicowej wspornikowej (tzw. belki Gerbera), niestosowanej wcześniej w Europie. Dwa takie przęsła o dużych rozpiętościach były użytkowane w moście pomiędzy 1632 a 1657 r. Analiza porównawcza znanych konstrukcji mostów europejskich z połowy XVII wieku wykazała, że najprawdopodobniej przęsła toruńskie były wówczas najdłuższe.
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Abstract

Henri Bergson as well as Gaston Milhaud undertake a radical critique of the conception of radical determinism because they both think that mind is able to act in a free and creative manner. In the article, I examine to what degree their arguments, aimed to prove this autonomy, converge. I inquire whether their endorsement of freedom of the mental acts led the two philosophers to the same conclusions regarding the cognitive extent of the intellect and therefore the parallel description of the status of scientific cognition.
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Abstract

The aim of this paper is to present an assessment of the slip influence on the deflection of the steel plate-concrete composite beams, which are a new type of a design concept. The proposed method is based on the procedure included in the PN-EN 1992-1-1, which has been modified with taking into consideration interface slip. The theoretical analysis was verified by experimental studies.
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Abstract

The aim of this study is to find the cost design of RC tension with varying conditions using the Artificial Neural Network. Design constraints were used to cover all reliable design parameters, such as limiting cross sectional dimensions and; their reinforcement ratio and even the beahviour of optimally designed sections. The design of the RC tension members were made using Indian and European standard specifications which were discussed. The designed tension members according to both codes satisfy the strength and serviceability criteria. While no literature is available on the optimal design of RC tension members, the cross-sectional dimensions of the tension membersfor different grades of concrete and steel, and area of formwork are considered as the variables in the present optimum design model. A design example is explained and the results are presented. It is concluded that the proposed optimum design model yields rational, reliable, and practical designs.
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Abstract

Shear walls are the most commonly used lateral load resisting systems in high rises. They have high plane stiffness and strength which can be used to simultaneously resist large horizontal loads while also supporting gravity loads. Hence it is necessary to determine effective and ideal locations of shear walls. Shear wall arrangement must be absolutely accurate, if not, it may cause negative effects instead. In this project, a study has been carried out to determine the effects of additions of shear walls and also the optimum structural configuration of multistory buildings by changing the shear wall locations radically. Four different cases of shear wall positions for G+10 storey buildings have been analyzed by computer application software ETABS. The framed structure was subjected to lateral and gravity loading in accordance with the Indian Standards provision and the results were analyzed to determine the optimum positioning of the shear walls.
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