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.
Mikołaj Miśkiewicz, Łukasz Pyrzowski, Krzysztof Wilde and Oskar Mitrosz
Development strategy for the port of Gdańsk assumes that , up to 2027, it will become the main transport centre in the Baltic Sea region. To this end , for many years work has been carried out to facilitate access to the port both by sea and land. One of the elements of extension of the port is the building of another terminal of Deepwater Container Terminal, Gdańsk. In this task, geotechnical operations aimed at appropriate preparation of subgrade for storage of containers and operation of cranes, have been especially important. Effectiveness of the assumed design solution of land-side girder for gantry crane has been verified by means of a technical monitoring system. This paper presents main elements of design the land-side girder of a new quay of the container terminal in Gdańsk, together with its computational analysis, as well as the results collected during a few months of observation, which have revealed real work of monitored elements.
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).
Mikołaj Miśkiewicz, Oskar Mitrosz and Tadeusz Brzozowski
Appropriate risk assessment plays a fundamental role in the design. . The authors propose a possible method of design risk mitigation, which follows recommendations included in Eurocode 7. The so-called “Observational Method” (OM) can produce savings in costs and programmes on engineering projects without compromising safety. The case study presented is a complex design solution that deals with the heavy foundations of a gantry crane beam as one of the elements of a Deepwater Container Terminal extension. The paper presents a detailed process of the design of the rear crane beam being a part of the brand new berth, together with its static analysis, as well as the long-term results of observations, which have revealed the real performance of the marine structure. The case presented is based on excessive preliminary field tests and technical monitoring of the structure, and is an example of a successful OM implementation and design risk mitigation.
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.