Mikołaj Miśkiewicz

System of monitoring of the Forest Opera in Sopot structure and roofing

The authors present a solution realized in Forest Opera (name in Polish: Opera Leśna) in Sopot (Poland) in connection with the modernization and construction of a new roof. The complicated structure of the roof of the facility and the used covering in form of membrane made of technical fabric required (for security reasons) to install the unit of devices allowing for the continuous geodetic monitoring of the facility. Monitoring of relocations in case of engineering structures of a complex design allows for the extended safety of their use. Realized (for this purpose) geodetic measurements require (to be useful) a high accuracy, full automation making the assessment independent from the human factor and the use of reference points. The main element of the presented system is a motorized total station used for the determination of roof cover relocations, whereas the complementary elements are vibration and temperature sensors and weather conditions monitoring station. Data recorders from the entire facility are connected to the computer central unit, providing automation of measurements and archiving of results along with their analysis. The problem occurring in the analyzed object is relatively unstable (subject to vibration) total station. Therefore, the solution implemented for Opera Leśna in Sopot assumes, that it is required to carry out measurements against reference points before every measurement of controlled points. On the basis of these measurements, for each measurement epoch the coordinates and relocation vectors for the tachymeter station are checked as well as analyses of an accuracy suitable for this process. The solution of this problem is useful for monitoring in other movable or subject to relocation engineering facilities. The article signalizes the problem of accuracy of surveying. For this purpose, the preliminary analyses of an accuracy were carried out. They made it possible to determine the expected errors of the reference points location in the designed network geometry and position of the total station for two variants: with and without taking into account the erroneous of reference points location. To summarize, we can say that the automatic measurement systems are an appropriate method for the continuous observation of the construction condition, however, they must be based on accurate, repeatable (for each measurement epoch) analyses of the observation of both monitored elements as well as their spatial references.

Technical Monitoring System for a New Part of Gdańsk Deepwater Container Terminal

Abstract 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.

Composite GFRP U-shaped footbridge

Abstract 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).

Preliminary Field Tests and Long-Term Monitoring as a Method of Design Risk Mitigation: A Case Study of Gdańsk Deepwater Container Terminal

Abstract 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.

The Effect of Fishing Basin Construction On the Behaviour of a Footbrdge Over the Port Channel

Abstract 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.

Load Testing of GFRP Composite U-Shape Footbridge

The paper presents the scope of load tests carried out on an innovative shell composite footbridge. The tested footbridge was manufactured in one production cycle and has no components made from materials other than GFRP laminates and PET foam. The load tests, performed on a 14-m long structure, were the final stage of a research program in the Fobridge project carried out in cooperation with: Gdansk University of Technology (leader), Military University of Technology in Warsaw, and ROMA Co. Ltd.; and co-financed by NCBR. The aim of the tests was to confirm whether the complex U-shape sandwich structure behaves correctly. The design and technological processes involved in constructing this innovative footbridge required the solving of many problems: absence of standards for design of composite footbridges, lack of standardized material data, lack of guidelines for calculation and evaluation of material strength, and no guidelines for infusion of large, thick sandwich elements. Obtaining answers during the design process demanded extensive experimental tests, development of material models, validation of models, updating parameters and extensive numerical parametric studies. The technological aspects of infusion were tested in numerous trials involving the selection of material parameters and control of the infusion parameters. All scientific validation tests were successfully completed and market assessment showed that the proposed product has potential applications; it can be used for overcoming obstacles in rural areas and cities, as well as in regions affected by natural disasters. Load testing included static and dynamic tests. During the former, the span was examined at 117 independent measurement points. The footbridge was loaded with concrete slabs in different configurations. Their total weight ranged from 140 kN up to 202 kN. The applied load at the most heavily loaded structural points caused an effect from 89% to 120%, compared to the load specified by standards (5 kN/m2 ). Dynamic tests included standard actions (walking, running, synchronous jumps) as well as aggressive tests, all designed to confirm the usability of the footbridge. The performed trials allowed the identification of the modal and damping parameters of the structure. The designated first natural frequency with a value of 7.8 Hz confirmed the correctness of the U-shape cross-section design due to its significant structural rigidity.

Dynamic Response of Forum Gdansk Structure due to Rail Traffic

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 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.

Damage Analysis of Tensioning Cable Anchorage Zone of a Bridge Superstructure, Using CDP Abaqus Material Model

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.

Próbne obciążenie kompozytowej kładki pieszo-rowerowej

W pracy podano zakres badan zrealizowanych podczas probnego obciązenia obiektu badawczego stanowiącego pelnowymiarowy kompozytowy most pieszo-rowerowy. Badane przeslo jest elementem projektu FOBRIDGE, ktory zostalo posadowione na obnizonych podporach na terenie kampusu Politechniki Gdanskiej. Wykonano testy statyczne i dynamiczne zgodnie z zalozonym programem badan.

Laminaty FRP w budownictwie ? charakterystyka materiału i aspekty projektowania

W artykule przedstawiono charakterystyke laminatow polimerowych wzmacnianych wloknami. W pierwszej cześci zaprezentowano teoretyczne modele materialowe, podstawowe zalezności naprezenie-odksztalcenie wlokien, matrycy oraz laminatu powstalego przez polączenie obydwu skladnikow. Na tej podstawie sformulowano zalecenia dotyczące praktycznego wykorzystania laminatu w kontekście jego wytezenia w projektowaniu elementow konstrukcyjnych. W drugiej cześci omowiono metody szacowania nośności kompozytow wloknistych z matrycą polimerową w kontekście metod zniszczenia: pierwszego (ang. First Ply Failure – FPF) i ostatniego wlokna (ang. Last Ply Failure – LPF) oraz związane z nimi wybrane kryteria inicjacji zniszczenia.