Bridges are vital in the operation of railway networks since any hindrances to their operation could suspend the flow of traffic. An important characteristic of bridges highly affecting their behavior is the skew angle. In this paper, a sensitivity analysis is performed to identify the effects of skew angle on train-track interaction for single-and double-sided crossings of a high-speed train. Comprehensive three-dimensional finite element models of the bridge and vehicle are developed, which are then calibrated using dynamic field test results. Effects of skew angle on shape modes and modal frequencies, acceleration values, and bridge displacement in various crossing speeds are studied. The results showed that if the bridge skew angle is more than 15°, it will affect the modal shape and frequency of the bridge. When the skew angle is less than 15°, the results of the bridge displacement are similar to those of the bridge with skew angle of zero. However, with the increase of the skew angle, the deformation value of the bridge decreases and the speed corresponding to the maximum displacement value also varies. Finally, the results of acceleration due to the speed and skew angle of the bridge are not the same in one-way and two-way passing states. Keywordsbridge-train interaction, high-speed train, finite element model, single-and double-sided crossings, dynamic field test verification 696|

No 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

Masonry bridges are among the main structures built along the road and railway routes. These structures are generally old and have historical value. Considering the increased axial load and passing speed from these bridges, an in-depth study of these structures and their potential is of paramount importance. In the present study, an old masonry arch bridge located in 475 km of Western Iranian railway is investigated. For the detailed modeling of this structure, a three-dimensional finite element method (3DFEM) was implemented to take into account the details of the bridge and the train passing over it. The developed model was calibrated and validated using the dynamic field test results. The obtained results showed that the increase in the axial load and train speed over the bridge must be done carefully because exceeding the travel speed of 90 km/h and increasing the axial load from 20 to 30 ton makes serious problems in the bridge and interrupts its performance. Furthermore, it was found that the adequacy factor of the bridge under the standard load of LM71 is over 2.