Assessing safety of a railway stone arch bridge by experimental and numerical analyses

Abstract

Assessing safety of a railway stone arch bridge by experimental and numerical analyses Bridge response to predefined loading schemes is described and recorded by instrumenting the structure with deflectometers and accelerometers. Test results suggest that although vertical deflections of mid-spans are almost constant for all crossing speeds, the root mean square of acceleration values are positively correlated with the crossing speed. Field test results are then used to calibrate and verify the 3D finite element model of the bridge, and the latter is employed to assess behaviour of the structure at the serviceability limit state. Ocjena sigurnosti kamenog lučnog željezničkog mosta eksperimentalnim i numeričkim analizama U radu je opisan odziv mosta na unaprijed definirana opterećenja, a određen je pomoću deflektometara i akcelerometara koji su u tu svrhu postavljeni na konstrukciju. Rezultati ispitivanja pokazuju da su vrijednosti korijena srednje kvadratne akceleracije pozitivno usklađene s brzinom prolaska, iako su vertikalni progibi na sredini raspona uglavnom konstantni pri svim brzinama prolaska. Rezultati dobiveni mjerenjima na terenu korišteni su za verifikaciju prostornog modela mosta, koji je korišten za ocjenu ponašanja konstrukcije pri graničnom stanju uporabivosti. Bewertung der Sicherheit der gemauerten Eisenbahn-Bogenbrücke durch experimentelle und numerische AnalysenIn der Arbeit wird die Reaktion der Brücke auf vordefinierte Belastungen beschrieben. Diese Reaktion wurde anhand von Deflektometern und Beschleunigungssensoren gemessen. Die Untersuchungsergebnisse zeigen, dass die Werte der Wurzel der mittleren quadratischen Beschleunigung mit der Durchgangsschnelligkeit positiv übereinstimmen, obwohl die vertikalen Verschiebungen in der Mitte der Breitspanne bei allen Durchgangsgeschwindigkeiten vorwiegend konstant sind. Die Messergebnisse vor Ort wurden für die Verifizierung eines Brückenraummodells verwendet, das für die Beurteilung des Verhaltens der Konstruktion beim Grenzzustand der Gebrauchstauglichkeit eingesetzt wurde. Schlüsselwörter:gemauerte Bogenbrücke, Methode der finiten Elemente, Grenzzustand der Gebrauchstauglichkeit, Grenzzustand der Tragfähigkeit

Three-dimensional Modeling of an Old Masonry Bridge and Assessing Its Current Capacity

“…The safety and serviceability of an old masonry arch bridge over 70 years old, which is still under service, was explored in this study. For this purpose, a comprehensive 3DFEM is developed and calibrated using the results of field dynamic load test results [10]. Then, after assessment of the effects of the moving load against the moving train and the effects of train speed and axle load on bridge responses, the current situation of the bridge in terms of serviceability and ultimate state is determined.…”

“…3 Bridge characteristics 475 Bridge is a structure with the serviceability age of 70 years and a length of 174 m. The bridge has four 25-m and six 8-m spans and operates with an axial load of 20 ton and a travel speed of 60 km [10].…”

“…The output of this study is a new formula for the first frequency, a value for damping ration, and different shape coefficients for old masonry arch bridges. Ataei et al [10] conducted some field dynamic tests on a stone bridge, calibrated their FE model, and analyzed the bridge under different conditions through dynamic analyses. The results revealed the complete safety of the bridge under operating load and inefficiency of the bridge under the standard LM71 loading.…”