0522476 20240111141035.220200224235959.9 17551307 85063548673 10.1088/1755-1315/221/1/012076 Bristol Institute of Physics Publishing 2019 10 s. E IOP Conference Series: Earth and Environmental Science Volume 221 1 cav_un_epca*05228821755-1307Earth and Environmental ScienceBristolIOPscience2019 ground-based radar interferometry disaster prevention dynamic loads radar measurement vertical deflections of bridge deformations temperature changes cav_un_auth*0284558 100 Talich Milan UTIA-B Zpracování obrazové informace Department of Image Processing ZOI ZOI Department of Image Processing CZ K Ústav teorie informace a automatizace AV ČR, v. v. i. online sborník http://library.utia.cas.cz/separaty/2020/ZOI/talich-0522476.pdf 1 MB cav_un_auth*0280658 FR-TI4/436 GA MPO The paper describes possibilities of the relative new technique – ground based radar interferometry for precise determining of the effect of temperature changes on vertical deflections of metal bridge structures. The ground based radar interferometry method is used in practice, among other things, for the quick contactless determination of vertical deflections of metallic railway bridge structures. The precision in deflection determination is up to 0.01 mm in real time. At the same time, it is also possible to capture and analyze the oscillation frequencies of the monitored object with a maximum frequency of up to 50 Hz. Deflections are determined at multiple points of the object at the same time, for example on individual cross beams. This allows to obtain both general and detailed information about the behaviour of the structure under its dynamic load and to monitor the impact of vehicle passages or their groups. Moreover, the ground based radar interferometry method is not sensitive to temperature changes. It can therefore to be used successfully to determine the effect of temperature changes on deflections and deformations of metallic objects, such as bridge structures. The influence of temperature changes is of two kinds. First, a direct effect on the very structure causes deformations due to thermal expansion of the metallic material. Furthermore, it is the effect on the character of the dynamic deformations caused by load changes - the transit of vehicles. This character varies with temperature, as demonstrated by experimental measurement in practice. Practical examples from practice documented by experimental measurements are given in the article. For example, at a 75m long metal bridge over a six-hour period with a temperature change of 25°C, a vertical deflection - lifting the bridge deck was about 9.5mm due to the thermal expansion of the material. There has been also a change in the nature of the dynamic deflections caused by train passes. At low night temperatures (about 14°C), deflections were much smoother than at high afternoon temperatures (about 39°C). cav_un_auth*0389896 World Multidisciplinary Earth Sciences Symposium (WMESS 2018) 20180903 20180907 Praha CZ DE 20000 20700 20705 2020 1 PR RVO:67985556 http://hdl.handle.net/11104/0307295 1 S 012076 0.149 Q4 2019 2019 Bristol Institute of Physics Publishing 85063548673 SCOPUS PUBMED WOS online sborník 1 MB cav_un_epca*0522882 World Multidisciplinary Earth Sciences Symposium (WMESS 2018) 1755-1307 1755-1315 Bristol IOPscience 2019 IOP Conference Series 221 Earth and Environmental Science