Łukasz Pyrzowski, Mikołaj Miśkiewicz and Jacek Chróścielewski
The paper analyses possible causes of failure of the rotating footbridge over the Ustka port channel. In July, 2015, strange behaviour of this object was observed in the form of excessive vibrations of bridge platform suspension rods, with the accompanying acoustic effects. A preliminary geotechnical analysis has revealed that this destructive effect was caused by the nearby construction works, namely construction of a fishing basin and communication routes in the area close to the bridge, which affected the bridge lashing rod foundation settings. Ground vibrations generated by certain construction activities were likely to have direct impact on decreasing the bearing capacity of these rods and increasing the susceptibility od the piles to extraction. After detecting the above problems in bridge operation, its geodetic monitoring was started. The data recorded during this monitoring, along with the results of force measurements in the rods, have made the basis for a series of numerical simulations, performed in the Finite Element Method (FEM) formalism. The bridge structure was analysed in the conditions defined as the emergency state. Extreme efforts of bridge elements and its dynamic characteristics were examined. A possible source of strange behaviour of the footbridge during its operation which was recognised during these simulations was the coincidence of the global natural frequency of the entire bridge structure with local vibrations of suspension rods, at the frequency approximately equal to 1 Hz. This situation was likely to lead to the appearance of the so-called internal resonance phenomenon. As a final conclusion of the research, recommendations were formulated on possible object oriented corrective actions.
Jacek Chróścielewski, Mikołaj Miśkiewicz, Łukasz Pyrzowski and Krzysztof Wilde
The paper presents proposals for the use of glass fiber reinforced polymer composites for the construction of engineering objects, known and commonly used in the shipbuilding industry. An example of a pedestrian footbridge was used in this case, which, despite the considerable thickness of the structural material, was made using infusion technology in one production cycle. The designed and produced footbridge span is durable, dynamically resistant, incombustible, easy to install and maintain, resistant to weather conditions and also aesthetically interesting. For footbridge production environmentally friendly PET foam core may be used. It may come from recycling of used plastic packages and which is produced with less energy consumption process and much less CO2 emission. The load bearing part of the structure (skin) is made of polymer laminate reinforced with glass fabrics (GFRP).
Kazimierz Jamroz, Krzysztof Wilde, Marcin Budzyński, Łukasz Jeliński, Jacek Chróścielewski, Stanisław Burzyński and Łukasz Pachocki
Key to understanding the needs and building road infrastructure management tools to prevent and mitigate run-off-road accidents is to identify hazards and their sources which are a result of wrong design, construction, installation and maintenance of road restraint systems . Building such tools requires advanced studies with field tests, simulations and models . Delivered under the Road Innovation programme, two research projects (ROSE and LifeROSE) are designed to help with that. The main aim of the projects is to develop a method to help with an optimal choice of road restraint systems.
M. Miśkiewicz, Ł. Pyrzowski, M. Rucka, K. Wilde and J. Chróscielewski
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 Głowny and Gdańsk Środmieście 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.
Krzysztof Wilde, Kazimierz Jamroz, Dawid Bruski, Marcin Budzyński, Stanisław Burzyński, Jacek Chróścielewski and Wojciech Witkowski
This paper addresses the problem of road safety regarding barrier placement as relative to the curb. A short summary of existing regulations is presented. Numerical simulations using the explicit finite element system Ls-Dyna are shown. In the analysis, variable distance between the barrier and the curb is assumed. The obtained result reveals that the distance has little impact on the working width of the barrier.