Instrumentation and fe analysis of a large-span culvert built under a railway, in Finland

Large span soil-steel culverts are rarely used in Finland as vehicular underpasses. The large span and low soil cover height together with high traffic loads place high demands on the construction of culvert backfills. Traffic-induced stress changes and the fatigue resistance of the plates play a major role in the endurance of a culvert. According to design calculations, the most critical section of the culvert is the crown. For this reason, the focus of this project is on the assessment of the structural behaviour and performance of the crown area. The structural performance of the culvert was verified by monitoring stress changes and deformations under live railway traffic, which proved the suitability of the multi-plated culvert built under a railway. As the project had only one constructed and monitored culvert, the monitoring results were used to construct an FE model to examine the effect of backfill variation on the culvert's structural behaviour.