FFU artificial timber sleepers: Measuring lateral resistance in ballasted tracks

摘要

The Institute of Road, Railway and Airfield Construction at the Munich University of Technology was commissioned by Sekisui Chemical to carry out tests at five locations on the railway line between Cologne and Aachen with different track configurations involving FFU artificial timber sleepers and natural timber ones in order to look into lateral resistance. Between the unconsolidated measurement and the consolidated one, the track underwent consolidation by having 33.9 million tonnes of load running over it. The lateral resistance measurements were carried out on a consolidated track using the underside of single unloaded sleepers of different heights (12 or 16 cm) both with and without reinforcements in the same material (of 2 or 6 cm). At 2 mm, the following lateral resistance values were measured as a mean of 14 or 15 sleepers for each of the track configurations in the consolidated state: 8.8 N/mm (FFU 12 cm), 16.6 N/mm (FFU 12 + 6 cm), 14.9 N/mm (FFU 16 cm), 16.8 N/mm (FFU 16 + 2 cm) and 14.8 N/mm (natural timber 16 cm). The16 + 2 cm FFU sleeper displayed the highest lateral resistance and thus outperformed the natural timber sleeper by approximately 14%. The 16 cm FFU sleeper with a smooth underside in the consolidated state has an equal performance to the 16 cm natural timber sleeper as regards lateral resistance (lateral resistance at 2 mm: 14.9 N/mm or 14.8 N/mm respectively). The effectiveness of reinforcing the sleeper was demonstrated especially for the 12 + 6 cm FFU sleeper. Compared with the measurements in the unconsolidated state, it was ascertained that the lateral resistance more than doubled for all five sleeper types.