Flexible culverts in sloping terrain: Numerical simulation of avalanche load effects

• The performance of flexible culverts is investigated when constructed in sloping terrain under defined avalanche loads.
• A number of 2D finite element models were created to simulate two case studies.
• The effect of soil cover, avalanche proximity, and soil configuration around the conduit were investigated.
• The downhill soil support configuration has a substantial effect on the flexural response of the structure.
• The increase in soil cover depth could considerably help in reducing the bending moments resulting from avalanches.

Avalanche protection concrete structures are expensive and their construction period is often influenced by the climatological conditions at site, which could result in prolonging the erection process and increase its associated costs. Given the short construction time of flexible culverts, such structures can be a cost-effective alternative to traditional protective measures. This article investigates the performance of flexible culverts – often referred to as soil–steel composite bridges (SSCB) – when constructed in sloping topography under avalanche loads. A number of 2D finite element models were created to simulate two case studies composed of a pipe arch and a high-profile arch. The models were generated to investigate the effect of soil cover depth, the avalanche proximity, and the change in soil support conditions around the conduit. The aim was to perceive and understand the changes in deformations and sectional forces under defined avalanche loads. The results enable to realise the effect of shallow soil covers in the pronounced change in bending moments due to avalanches. The proximity of avalanche deviation point has a great influence on the structural performance, though increasing the soil cover depth could considerably help in reducing the bending moments resulting from avalanches. It is also found that the downhill soil support configuration has a substantial effect on the flexural response of the structure.