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Number of results: 10
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Abstract

The main issue of this article are eco-bridges, pedestrian-friendly imaginary sites (enclave) of greenery in urban tissues. Discussed cases include the implementations of projects such as: the High Line in New York and the Garden Bridge in London. The main theme of the article is to compare the green bridges in the urban tissue embedded with “living root bridges”. The author of the article highlights the potential limits for “living root bridges” in the urban tissue, resulting from the climate, time of their creation and limits of urban space. She also notes the strong tendency to create green areas in the “concrete” urban structure, but also the use of artificial materials in tissue of “living root bridges”.
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Abstract

Łazienki królewskie w Warszawie wyróżnia mnogość form małej architektury. Stanowią one umieszczony w sercu miasta zakątek historii polskiej kultury i sztuki wpleciony w scenerię krajobrazowego ogrodu. Przejrzysty, inspirowany przyrodą układ przestrzenny ogrodu silnie akcentowany jest przedstawieniami rzeźbiarskimi i formami małej architektury – mosty. Zarówno przedstawienia rzeźbiarskie, jak i formy mostów stanowią uzupełnienie kompozycyjne całości założenia. Czerpiący natchnienie ze sztuki antycznej, chińskiej najznamienitsi artyści tworzyli tu dzieła, które harmonizując z otoczeniem przemieniły park w miejsce posiadające niemożliwą do wydzielenia na poszczególne elementy całość o symbolicznym i duchowym wymiarze.
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Abstract

W artykule zostało omówionych sześć rozwiązań konstrukcyjnych ustroju niosącego zastosowanych w dawnym wiślanym moście w Wyszogrodzie, które dzisiaj nie są już stosowane. Opisano je na podstawie danych zawartych w źródłach pisanych, mapach topograficznych, dawnych fotografiach, pocztówkach i informacjac prasowych, które zebrane zostały w monografi i pt. „Dawny most przez Wisłę w Wyszogrodzie”, opublikowanej przez autora w 2016 r. Konstrukcje tymczasowe mostu były utrzymywane przez długi, 77-letni okres do czasu zbudowania w 1999 r. nowego trwałego mostu przez Wisłę koło Wyszogrodu. Dawny most znajdował się w ewidencji zabytków architektury i budownictwa prowadzonej przez ówczesny Ośrodek Dokumentacji Zabytków w Warszawie. Niestety nie doczekał się wpisu do rejestru, decyzji o jego prawnej ochronie i został rozebrany.
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Abstract

Modern regulations concerning railway bridges are based on the approach of structural dynamics, which is described in PN-EN standards. This paper presents the results of theoretical dynamic analysis of the HSLM-A train set loading on the structure of a pre-stressed concrete arch bridge - the first railway bridge of its type which was built in Poland (completed in 1959). The recommendations of PN-EN have been followed and modal analysis was carried out to define the sensitivity of the structure to chosen eigenforms. Additionally the paper presents a course of calculations and the conclusions obtained from the analysis of displacements, accelerations, and bending moments induced in the structure through a simulated passage of a high-speed train in the context of the requirements of PN-EN Standards. The conclusions from the current calculations can be used for dynamic analysis of bridges of similar structural solutions.
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Abstract

On the 14th of February, 2015, a huge fire broke out on Łazienkowski Bridge; a five span bridge, 423 m long and 28 m wide, built in the years 1972-74. It was a fully steel structure with four plate girders and orthotropic deck. The fire started under the first span during the replacement of wooden service decks. The next day, the Department of Bridges of the Warsaw University of Technology was designated to conduct an expertise material investigation, geometrical verification, and FEM model analysis. The subject of this paper concentrates on geometrical issues. The main difficulty of this task was the lack of full reference data regarding the bridge's original structure. The old design was incomplete and there was no actual surveying results for the undamaged structure. As a conclusion, some remarks focused on surveying measurements and on the final decision regarding this bridge are given. It was eventually exchanged into a brand new one and put into public use on the 28th of October, 2015.
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Abstract

The paper presents selected aspects of dynamic numerical simulations of an orthotropic steel railway bridge loaded by high-speed trains. The model of moving loads was adopted in accordance with the models set out in the applicable standards. The current European code requirements are referred in which the computer calculations of the dynamic response of the structure are the basis for assessing the suitability of the structure to carry high-speed rail traffic ( v > 160 km/h ). In this research the calculations are based on the author's method of generating traffic roads in Abaqus FEM environment. lt is emphasized in the paper that in most commercial FEM codes (including Abaqus), moving loads are not implemented in modules responsible for defining of loads. The author's approach to this issue allowed to obtain results confirming its adequacy. In the longer term, the authors will develop a plan to adapt this algorithm in order to generale traftic loads on bridges discretized as spatial and plane numerical models.
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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

This study was carried out on the background of Sutong Bridge project based on fracture mechanics, aiming at analyzing the growth mechanism of fatigue cracks of a bridge under the load of vehicles. Stress intensity factor (SIF) can be calculated by various methods. Three steel plates with different kinds of cracks were taken as the samples in this study. With the combination of finite element analysis software ABAQUS and the J integral method, SIF values of the samples were calculated. After that, the extended finite element method in the simulation of fatigue crack growth was introduced, and the simulation of crack growth paths under different external loads was analyzed. At last, we took a partial model from the Sutong Bridge and supposed its two dangerous parts already had fine cracks; then simulative vehicle load was added onto the U-rib to predict crack growth paths using the extended finite element method.
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Abstract

This paper presents simulation results of the consolidation process of the flotation waste landfill “Żelazny Most”. The mathematical model used in presented research is based on Biot’s model of consolidation and is extended with rheological skeleton. The load is the mass pressure of the landfill itself. The initial point selected for calculations was based on the ground water level calculated in a landfill. The creeping process in this waste landfill was analyzed along the north – south section. The solution is therefore 2D with the assumption of a plane strain state. Effective model parameters data were obtained in laboratory tests on the material from the waste landfill. Results obtained for a stress state in a storage state can help to determine whether the adopted linear model of visco-elastic medium does not lead to changes in the Coulomb – Mohr potential yield, showing the emergence of plasticity of material storage areas.
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Abstract

The subject of the research is one of the largest World’s mine tailings disposal sites, i.e. Żelazny Most in the Legnica-Głogów Copper Mining District (south-western Poland), where flotation tailings are poured out after copper ore treatment. The protective hydraulic barrier made of 46 vertical drainage wells was characterized and evaluated in view of reduction of major contaminants (Cl, Na, SO4, Ca) migrating from the facility to its foreground. The efficiency of groundwater protection was determined on the basis of a new approach. In applied method the loads of characteristic and commonly recognizable compounds, i.e. salt (NaCl) and gypsum (CaSO4) were calculated, instead their chemical components. The temporal and spatial variability of captured main contaminants loads as well as its causes are discussed. The paper ends with the results of efficiency analyses of the barrier and with respect to the predicted increase in contaminant concentrations in the pulp poured out to the tailings site.
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