The construction of protection and safety infrastructure in mountainous environments represents a major technical and environmental challenge. In particular, the installation of an avalanche and rockfall protection tunnel in the Coler area, in the heart of the Rabbi Valley, is part of a strategic project aimed at ensuring safe access to the trail network of the Stelvio National Park, one of the most important geoparks in the Italian Alps.
This project stands out not only for its engineering features, but also for the strong focus on environmental protection and the selection of waterproofing solutions specifically designed to perform under extreme climatic conditions.
Environmental context and purpose of the intervention
The municipal road in the Coler area—an ideal starting point for exploring the 1,500 km of trails within the Stelvio National Park—has been periodically affected by landslides and rockfalls caused by the destabilisation of mountain slopes, exacerbated by extreme weather events. Changing climatic conditions, characterised by heavy rainfall alternating with prolonged dry periods, accelerate the disintegration of rock masses and surface materials, compromising road safety and the local ecosystem.
The intervention involved the construction of a tunnel designed to mitigate the risks associated with landslides and avalanches, protecting both traffic and the surrounding environment. Selecting a waterproofing system suitable for these demanding conditions was essential to ensure long-term structural integrity, preventing water infiltration that could undermine stability and cause material degradation.
Technologies and materials used
To ensure optimal performance under severe climatic conditions, a high-performance, two-layer waterproofing system was adopted, providing long-lasting durability and resistance.
The first waterproofing layer consists of COPERBIT S, an elastomeric bituminous liquid-applied membrane. Formulated with bitumen modified with elastomers, it is cold-applied and solvent-free, ensuring easy, uniform application while offering greater environmental compatibility. Once cured, its elastic formulation forms a tough, flexible and waterproof film, capable of withstanding prolonged water ponding—an essential requirement in environments subject to highly variable weather conditions.
As the top layer, ASTROFLEX TECH was used, a bituminous membrane featuring an elastomeric compound obtained by modifying distilled bitumen with an SBS (Styrene-Butadiene-Styrene) polymer.
Thanks to its high elasticity and excellent resistance to thermal ageing, this membrane ensures outstanding flexibility at the low temperatures typical of alpine areas, as well as superior durability compared to traditional bituminous membranes. The elasticity provided by SBS technology allows the waterproofing system to effectively withstand mechanical stresses over time, preserving the integrity of the structure in the long term.
Environmental considerations and benefits
The use of low environmental impact products combined with high-performance technologies reflects an approach focused on protecting the mountain environment, while minimising interference with the landscape and surrounding ecosystem. Material selection favoured ready-to-use solutions with fast curing times and high resistance to humidity and frost, which are characteristic of the area.
Moreover, the flexibility and structural stress resistance of the membranes used allow for effective management of both dynamic and static loads, contributing to a durable, long-term solution and reducing the environmental impact associated with future maintenance and restoration works.
The waterproofing intervention carried out on the Val di Rabbi tunnel is a clear example of how advanced technologies and environmental responsibility can be successfully integrated in sensitive alpine contexts. Collaboration between engineers, technicians and specialised companies made it possible to deliver a project that enhances road safety while protecting the territory, supporting sustainable access to the Stelvio National Park.
Taking part in an initiative that combines safety, sustainability and innovation further strengthens our commitment to promoting state-of-the-art technical solutions for the protection of valuable mountain environments.
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For further details and technical information, please refer to the technical data sheets:
ASTROFLEX TECH
This project is published on the Ingenio portal.
