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Olaszek P.♦, Świercz A., Boscagli F.♦, The integration of two interferometric radars for measuring dynamic displacement of bridges,
Remote Sensing, ISSN: 2072-4292, DOI: 10.3390/rs13183668, Vol.13, No.18, pp.3668-1-18, 2021Streszczenie: Measurements of displacements of bridges under dynamic load are particularly difficult in the case of structures where access to the area under the tested structure is impossible. Then, remote measurement methods are preferred, such as interferometric radar. Interferometric radar has high accuracy when measuring displacement in the direction of its target axis. The problems appear when a bridge vibrates in two directions: horizontal (lateral or longitudinal) and vertical. The use of one radar to measure those vibrations may be impossible. This paper presents the application of a set of two interferometric radars to measure vertical vibration and horizontal longitudinal vibration with high accuracy. The method was positively verified by experimental tests on two railway bridges characterized by different levels of horizontal displacement. The accuracy of the radar measurements was tested by the direct measurement of vertical displacements using inductive gauges. In conclusion, in the case of vertical displacement measurements using one interferometric radar, the influence of horizontal displacements should be excluded. In the case of locating radars at the area of bridge supports, it is necessary to either use a set of two radars or first investigate the magnitude of possible horizontal displacements in relation to vertical displacements. Słowa kluczowe: bridge monitoring, interferometric radar, remote measurements, dynamic vertical and horizontal displacements Afiliacje autorów:
Olaszek P. | - | Instytut Badawczy Dróg i Mostów (PL) | Świercz A. | - | IPPT PAN | Boscagli F. | - | inna afiliacja |
| | 100p. |
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Błachowski B., Świercz A., Ostrowski M., Tauzowski P., Olaszek P.♦, Jankowski Ł., Convex relaxation for efficient sensor layout optimization in large‐scale structures subjected to moving loads,
Computer-Aided Civil and Infrastructure Engineering, ISSN: 1093-9687, DOI: 10.1111/mice.12553, Vol.35, No.10, pp.1085-1100, 2020Streszczenie: This paper proposes a computationally effective framework for load‐dependent optimal sensor placement in large‐scale civil engineering structures subjected to moving loads. Two common problems are addressed: selection of modes to be monitored and computational effectiveness. Typical sensor placement methods assume that the set of modes to be monitored is known. In practice, determination of such modes of interest is not straightforward. A practical approach is proposed that facilitates the selection of modes in a quasi‐automatic way based on the structural response at the candidate sensor locations to typical operational loads. The criterion used to assess sensor placement is based on Kammer's Effective Independence (EFI). However, in contrast to typical implementations of EFI, which treat the problem as a computationally demanding discrete problem and use greedy optimization, an approach based on convex relaxation is proposed. A notion of sensor density is applied, which converts the original combinatorial problem into a computationally tractable continuous optimization problem. The proposed framework is tested in application to a real tied‐arch railway bridge located in central Poland. Słowa kluczowe: optimal sensor placement, effective independence method, Fisher information matrix Afiliacje autorów:
Błachowski B. | - | IPPT PAN | Świercz A. | - | IPPT PAN | Ostrowski M. | - | IPPT PAN | Tauzowski P. | - | IPPT PAN | Olaszek P. | - | Instytut Badawczy Dróg i Mostów (PL) | Jankowski Ł. | - | IPPT PAN |
| | 140p. |
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Olaszek P.♦, Wyczałek I.♦, Sala D.♦, Kokot M.♦, Świercz A., Monitoring of the static and dynamic displacements of railway bridges with the use of inertial sensors,
SENSORS, ISSN: 1424-8220, DOI: 10.3390/s20102767, Vol.20, No.10, pp.2767-1-24, 2020Streszczenie: In the case of the monitoring of bridges, the determination of vertical displacements is one of the most important issues. A new measuring system has been developed and implemented for assessment of railway bridges based on measurements of the structural response to passing trains. The system uses inertial sensors: Inclinometers and accelerometers that do not need any referential points. The system records signals related to the passage of a train over a monitored bridge. The signals from inclinometers before the train's entry are used to determine the static movement. Integrated signals from inclinometers and accelerometers are used to determine dynamic displacements when the train goes through the bridge. Signals from inclinometers are used to determine the so-called "quasi-static" component of the displacement and signal from the accelerometer to determine the dynamic component. Field tests have been carried out on a viaduct along a high-speed railway line. Periodic comparative measurements are carried out using a Total Station to verify static measurements and using inductive sensors to verify dynamic measurements. Tests of the system carried out so far have proven its usefulness for monitoring bridges in a high-speed railway (up to 200 km/h) with high accuracy while determining dynamic displacements. Słowa kluczowe: bridge monitoring, dynamic and static displacements, inertial sensors, total station, indirect measurement Afiliacje autorów:
Olaszek P. | - | Instytut Badawczy Dróg i Mostów (PL) | Wyczałek I. | - | Poznan University of Technology (PL) | Sala D. | - | inna afiliacja | Kokot M. | - | inna afiliacja | Świercz A. | - | IPPT PAN |
| | 100p. |
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Olaszek P.♦, Świercz A., Wyczałek I.♦, Kołakowski P.♦, Szadkowski K.♦, Moduł pomiaru i oceny odpowiedzi eksploatowanych kolejowych konstrukcji mostowych,
Mosty, ISSN: 1896-7663, Vol.3-4, pp.22-26, 2017 | | 3p. |