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Rock in motion: rockfall

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We conduct research into rockfall processes in order to be able to evaluate the risk of falling rocks more accurately and to improve protection against rockfalls. To this end, we send rocks hurtling down from great heights – either as part of field studies,  in the laboratory or simulated in a computer model.


In a mountainous country like Switzerland, rockfalls are a common occurrence. As they can lead to fatal accidents and damage roads and buildings, we are looking at ways to protect the public against rockfalls, e.g. through the use of protective fences, rockfall galleries or dams, and protection forests.

How do rocks fall?

We examine how rocks of different shapes fall: how fast, how high and how far do they bounce? To find out, we insert sensitive probes inside natural and artificial boulders and roll them down slopes in the laboratory and on field sites. This enables us to measure the boulders' trajectories, acceleration and rotational velocities.


This information is fed into our RAMMS::Rockfall software. This allows us to simulate boulders falling down over flat or steep, forested or rocky terrain. The model calculates the force with which the boulders would land and whether they would hit infrastructure or buildings. This helps engineers verify the cantonal rockfall hazard maps.

The forest is often the best and most cost-effective form of protection (Protection forest) against rockfalls. At our site in Cadenazzo, we are researching for example whether the protective function of the forest will change if the tree of heaven, an invasive tree species in Ticino, colonises the forest. To that end, we are examining how robust these neophytes are against the force of rockfalls through field and laboratory experiments.