Avalanche dynamics and its impact on transport infrastructure: A case study of the Podljubelj Avalanche Tunnel, Slovenia.

This thesis begins with an in-depth analysis of the avalanche phenomenon. After a general overview, the study examines the snowpack, avalanche classification, and modelling techniques used to assess avalanche dynamics, with a focus on the RAMMS Avalanche software. The first section also includes an overview of defence structures and avalanche risk mitigation strategies, with an in-depth analysis of the impact forces exerted by avalanches on structures, with particular focus on their effects on avalanche protection tunnels. The research then explores the spatial and temporal distribution of avalanches, comparing the southwestern and southeastern Alps. The spatial analysis focuses on avalanche event density per square kilometre in selected regions, while the temporal analysis investigates the relationship between avalanche risk and climate change, considering snow depth and altitude. The Podljubelj tunnel case study is introduced with a description of its geographic setting, avalanche-prone site, and structural characteristics. The study then analyses historical avalanche data; where such data is unavailable, climatic and snow-related information is utilized to estimate snow depth values for use in RAMMS simulations. Following a brief introduction to the software, avalanche simulations are performed with varying snowpack heights in the release area. Each scenario accounts for different snow cover conditions, producing estimates of runout distance and potential interference with the road in the event of high-magnitude avalanches, thereby providing valuable insights for risk management. In the final section, the probability of a vehicle being halted by an avalanche is calculated, alongside an analysis of the costs associated with road closures and snow removal. These factors are then compared with the expenses involved in constructing permanent mitigation structures (e.g., avalanche tunnels), which require minimal maintenance over time.