Vrati se na GFOS

Novosti

Elektronički časopis Građevinskog fakulteta Osijek, e-GFOS je online časopis otvorenog pristupa koji objavljuje znanstvene i stručne članke u svim područjima građevinarstva i arhitekture.
Elektronički časopis Građevinskog fakulteta Osijek, e-GFOS časopis čiji se članci recenziraju te važan i pouzdan izvor aktualnih informacija o razvoju građevinarstva i arhitekture. Teme u domeni časopisa su orijentirane na betonske konstrukcije, građevinske materijale, mehaniku konstrukcija, geomehaniku, temeljenje, vodne resurse, hidrauliku, interakciju fluida i konstrukcija, organizaciju građenja, arhitekturu i urbanizam te ostala relevantna građevinska i arhitektonska područja.

Number 21 - December, 2020.


     

FORM-MAKING METHODS IN LANDFORM ARCHITECTURE

Autori: Y. Kuznietsova, H. Osychenko

Sažetak: In this study, we consider a critical challenge in architectural design methodology-methods of form making in landform architecture. Based on the authors’ methodology, the approaches and methods of form making are specified and systematized, depending on the algorithm of the form-making process and the basic principles of building composition. The approaches to architectural form making, including image-based, generative, and functional approaches are determined. The methods within the framework of the image-based approach are identified. These methods include natural «mimicry» and metaphorical methods, as well asan image-based and combinatorial method. Furthermore, the principles and techniques of form-making methods are examined, and their capability and potential to create esthetically expressive and poetically shaped buildings, which can be integrated into existing natural landscapes, are determined

Ključne riječi: Landform architecture; natural “mimicry” method; metaphorical method; image-based and combinatorial method; stylization

PDF preuzimanje
PDF preuzimanje

INFLUENCE OF NUMERICAL SOIL MODEL TYPE ON DYNAMIC RESPONSE OF REINFORCED CONCRETE FRAME STRUCTURES

Autori: P. Ravlić, I. Kraus

Sažetak: In engineering practice, numerical models of structures are typically supported using nondeformable media. However, the compliance and stratification of the underlying soil influence the seismic response of the structure. Its influence on structures subjected to dynamic loads has been investigated using various approaches to soil foundation modeling. This study was conducted for 70 different cases. Three actual soil profiles and two structures were analyzed, and the soil was modeled in three ways. Dynamic analysis was performed using five records of previous earthquakes. Finally, the relationship between the magnitude of the top displacement of the structure and the frequency content of ground motions was established.

Ključne riječi: Foundation soil, reinforced concrete frame structure, ground motion records, predominant excitation period, mean excitation period, soil stratification

PDF preuzimanje
PDF preuzimanje

NUMERICAL ANALYSIS OF WELDED BEAM-COLUMN JOINTS IN ALUMINUM STRUCTURES

Autori: T. Hržić, I. Boko, N. Torić

Sažetak: The objective of this study is to compare the performance for welded beam-column joints in aluminum structures using moment-rotation diagrams and to evaluate the influence of welding on joint rigidity. A nonlinear numerical calculation of welded beam–column joints is performed using the finite element method. Material and geometric nonlinearities were included in the model. The connection was analyzed for two cases: variants with and without welded stiffener plates. Two material models were used. The first was derived from the applicable standard for aluminum structures, while the other was based on the results of a previous material study and calibrated using a separate numerical calculation. From the results of the calculations, moment-rotation diagrams for different geometries and material properties of joints were constructed and compared. The obtained moment-rotation diagrams for the stiffened and unstiffened joints demonstrate that stiffening of the joints in aluminum structures improves the properties of the joint in terms of higher rigidity, resistance, and ductility, regardless of the existence of the heat affected zone.

Ključne riječi: Aluminum; heat affected zone; welded beam-column joint; nonlinear analysis; material nonlinearity; finite-element method.

PDF preuzimanje
PDF preuzimanje

PROVIDING THE THERMAL RELIABILITY OF WINDOW JUNCTIONS DURING THE THERMAL MODERNIZATION OF CIVIL BUILDINGS

Autori: M. Pashynskyi, S. Dzhyrma, V. Pashynskyi, V. Nastoyashchiy

Sažetak: In order to assess the possibility of condensation on an internal window jamb surface, the temperature fields of window junctions to brick and precast concrete walls of civil buildings were analyzed, which were massively produced in the second half of the twentieth century. This study obtained the dependences of the jamb temperature on the thickness of the additional insulation layer and the outdoor temperature. Additionally, it showed the possibility of adjusting the jamb temperature by shifting the window frame inside the building. Outside air temperatures at which no condensation will occur in the initial junction structures and after thermal modernization by additional facade insulation were determined. The results can be used to replace worn-out windows and during the thermal modernization of buildings.

Ključne riječi: Brick walls; precast concrete walls; thermal modernization; block frame window; condensation.

PDF preuzimanje
PDF preuzimanje

NUMERICAL INVESTIGATIONS OF FLUSHING TIME IN SMALL MARINAS

Autori: : I. Bartolić, G. Lončar, D. Bujak, D. Carević

Sažetak: This paper presents the results of 2D and 3D numerical simulations of sea circulation and water mass exchange for a marina with hypothetical dimensions (L/B=2 and L/B=0.5) to calculate the return flow factor. The return flow factor b was analyzed in relation to the marina entrance width, sea current velocity outside the marina (0, 1, 2, and 5 cm/s) and the sea surface level oscillation dynamics. The basic comparative parameter is the e-flushing time, Tf. The intensity of forced circulation is calculated to achieve time Tf of less than 10 days. The impact of the wind field on the e-flushing time for different marina widths was analyzed using a 3D numerical model. The numerical simulation results indicate that the e-flushing time Tf depends on the amplitude of the tidal signal, secondary to the width of the marina inlet, and the smallest amount on the velocity field in the outer region. Conversely, the return flow factor b depends on the width of the marina entrance, less on the tidal signal amplitude, and least on the current velocity outside the marina if currents are ≥ 1 cm/s. Forced circulation of 1 m3/s is only required for the marina with a smaller tidal amplitude (position Dubrovnik) to achieve Tf<10 days. If at the observed location wind is a dominant sea circulation generator, a wider marina entrance will allow faster sea exchange.

Ključne riječi: Return flow factor; marina flushing; entrance width; tidal range; wind; Adriatic Sea; numerical model.

PDF preuzimanje
PDF preuzimanje

MODIFICATION OF ASPHALT MIXES USING WHITE CEMENT DUST AND IRON FILINGS AS A FILLER

Autori: I. Khliefat, M. Msallam

Sažetak: The possibility of using white cement dust and iron filings as fillers to modify asphalt mix properties was investigated. Numerous aggregate tests were conducted, including sieve analysis, specific gravity, absorption, and abrasion tests. Several bitumen tests were also conducted, including penetration, softening point, ductility, flash point, and specific gravity tests. Marshall properties were used to evaluate the physical performance of the mixtures. The construction of pavements with iron filings in hot asphalt mixtures is not recommended, but white cement dust powder or limestone powder can be beneficial. A 5% content was observed to be the best white cement dust content. There is no clear relationship between air voids and the percentages of white cement dust and iron filings, as the curve fluctuates. The use of white cement dust as a filler always exhibits better results; therefore, using white cement dust widely is recommended over using iron filings.

Ključne riječi: Asphalt; fillers; iron filings; white cement dust

PDF preuzimanje
PDF preuzimanje

Časopis sufinancira Ministarstvo znanosti i obrazovanja