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Povzetek: Bridge weigh-in-motion systems use instrumented bridges or culverts to weigh vehicles as they pass over the structures. They also provide data to allow the calculation of several bridge performance indicators. The article starts with the basics of a bridge weigh-in-motion system and briefly describes two key bridge performance indicators, girder distribution factor and dynamic amplification factor, which are also derived from B-WIM measurements. The central part of the article focuses on monitoring of influence lines, the third key parameter that characterises the bridge performance under traffic loads. First, the method of calculating the bending moment influence lines from random heavy traffic is described. A coefficient of rotational stiffness is introduced, which defines the shape of influence lines around the supports as a linear combination of the ideal simply supported and fixed supported influence lines, to allow quantifying the influence line changes. Then the long-term monitoring of influence lines is investigated on four different single-span test bridges. The initial focus is given on the examination of the effect of temperature on the shape of influence lines. Finally, two sets of influence lines are compared on one test bridge, one from before and the other from after replacing the expansion joints and bearings. The work done so far confirms that calculating of influence lines from random vehicles with a B-WIM system is entirely feasible and that differences in their shape can be detected on single-span bridges. What remains to be investigated is the comparison of these differences to the actual damages and under which circumstances the proposed procedure can compete with or better the routine bridge inspection and the conventional monitoring techniques.
Ključne besede: bridge loading, bridge response, temperature dependency, influence line, monitoring
Objavljeno v DiRROS: 12.09.2023; Ogledov: 330; Prenosov: 126
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Povzetek: Stresni zlomi medenice po obsevanju so že dolgo znana posledica obsevanja tumorjev v področju medenice. Čeprav so zlasti v področju sakruma relativno pogost pojav, je njihova diagnostika zaradi nespecifičnosti simptomov težavna. V tem preglednem članku smo pregledali literaturo, ki zajema etiologijo, incidenco, dejavnike tveganja, simptome in diagnostiko ter zdravljenje in preprečevanje stresnih zlomov medenice po obsevanju. Na podlagi pridobljenih podatkov smo poskušali strniti in predstaviti najdene ugotovitve z navedenih področij, ki bi nam bile lahko v pomoč v vsakodnevni radioterapevtski klinični praksi, saj standardiziranih priporočil na tem področju nismo našli.
Ključne besede: stresni zlomi medenice, obsevanje, incidenca
Objavljeno v DiRROS: 27.07.2023; Ogledov: 294; Prenosov: 75
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Povzetek: This study describes the development and testing of a railway bridge weigh-in-motion (RB-WIM) system. The traditional bridge WIM (B-WIM) system developed for road bridges was extended here to calculate the weights of railway carriages. The system was tested using the measured response from a test bridge in Poland, and the accuracy of the system was assessed using statically-weighed trains. To accommodate variable velocity of the trains, the standard B-WIM algorithm, which assumes a constant velocity during the passage of a vehicle, was adjusted and the algorithm revised accordingly. The results showed that the vast majority of the calculated carriage weights fell within %5% of their true, statically-weighed values. The sensitivity of the method to the calibration methods was then assessed using regression models, trained by di%erent combinations of calibration trains.
Ključne besede: bridge weigh-in-motion, railway bridge loading, bridge instrumentation, B-WIM
Objavljeno v DiRROS: 22.05.2023; Ogledov: 278; Prenosov: 143
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Povzetek: The bee-mimicking hoverfly species Criorhina pachymera shows pronounced geographical variation in abdominal colour pattern. Based on 218 records from 22 European countries, we describe six abdomen forms divided over two main groups. Group A in western, northern and central parts of Europe contains abdomen forms A1–A3 with slender pollinose bands on the third and fourth tergite. Group B in south-eastern Europe contains forms B1–B3 with broad pollinose bands. These groups are separated by the Alps and the Carpathians, such as the separation of the original distributions of the two main postglacial recolonization lineages of honey bees in Europe. As these honey bee groups differ by the width of the pollinose bands on the third to fifth tergite, Batesian mimicry can explain the group distribution of C. pachymera with slender or broad pollinose bands. The different forms of C. pachymera in both groups are categorised by the extent of orange colouration on the second and third tergite. The darkest form A1, has a widespread distribution in Europe. Intermediate bright forms A2 and A3 occur predominantly in a belt along the southern margin of the group A distribution and in Sweden. Dark form B1 and intermediate bright form B2 occur on the Balkan peninsula and in neighbouring regions. The brightest form B3, is found in Italy, Switzerland (Ticino) and Greece. There is an average increase in the extent of orange colouration on the second and third tergite with decreasing geographical latitude, making temperature a likely additional cause for the described abdominal colour variation.
Ključne besede: hoverflies, colour variation, biogeography, Batesian mimicry, citizen science data
Objavljeno v DiRROS: 28.03.2023; Ogledov: 484; Prenosov: 211
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Povzetek: Landslide monitoring is a mandatory step in landslide risk assessment. It requires collecting data on landslide conditions (e.g., areal extent, landslide kinematics, surface topography, hydrogeometeorological parameters, and failure surfaces) from different time periods and at different scales, from site-specific to local, regional, and national, to assess landslide activity. In this analysis, we collected information on landslide monitoring techniques from 17 members of the Earth Observation and Geohazards Expert Group (from EuroGeoSurveys) deployed between 2005 and 2021. We examined the types of the 75 recorded landslides, the landslide techniques, spatial resolution, temporal resolution, status of the technique (operational, non-operational), time of using (before the event, during the event, after the event), and the applicability of the technique in early warning systems. The research does not indicate the accuracy of each technique but, rather, the extent to which Geological Surveys conduct landslide monitoring and the predominant techniques used. Among the types of landslides, earth slides predominate and are mostly monitored by geological and engineering geological mapping. The results showed that Geological Surveys mostly utilized more traditional monitoring techniques since they have a broad mandate to collect geological data. In addition, this paper provides new insights into the role of the Geological Surveys on landslide monitoring in Europe and contributes to landslide risk reduction initiatives and commitments (e.g., the Kyoto Landslide Commitment 2020).
Ključne besede: landslide, monitoring techniques, geological data, Geological Surveys of Europe
Objavljeno v DiRROS: 30.01.2023; Ogledov: 511; Prenosov: 214
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