Rockfalls are increasingly threatening roads, railway lines and settlements – exacerbated by climate change and extreme weather conditions. In order to test protection systems even more realistically, Geobrugg conducted a globally unique test on 1 October 2025: for the first time, a flexible rockfall protection barrier was exposed to two simultaneous impacts – and withstood them.
Real conditions instead of lab scenarios
Standardised tests for rockfall barriers have so far focused on a single, precisely defined impact in the centre. The reality is different: in nature, several rocks hit the barriers at the same time, often outside the centre. With the ROCCO barrier, Geobrugg transfers these real conditions into testing practice. The barrier with a nominal energy of 3000 kJ was tested with two blocks weighing 4.8 tonnes each (50% of the total energy) – one impact in the centre and one in the adjacent edge field.
Results of the simultaneous test
The multiple impact resulted in higher forces than in the classic single test – due to the limited mesh deformation. The special butterfly mesh geometry of the ROCCO barrier proved to be a decisive advantage here: it distributes the loads better and reduces peak forces on the supports.
Helene Lanter, CTO Geobrugg: ‘With the additional tests, we are closing the gap between standard and reality. Our ROCCO protective barriers are designed for robustness – for high-risk zones where frequent impacts occur.’
Extended testing philosophy
The test marks the next step towards realistic safety verification. Field observations and large-scale tests show that rotating or flat blocks generate asymmetrical loads that standard tests have not taken into account until now. Geobrugg is therefore specifically expanding its testing methodology to include such realistic load cases.
Significant media coverage
The pioneering test in Walenstadt also attracted considerable media attention. Numerous specialist and regional media outlets reported on the world’s first simultaneous test of a rockfall barrier:
- Schutz vor Steinschlag – Steigende Gefahr von Steinschlägen: Stresstest am Berg – News – SRF
- Steinschlagschutz auf neuem Niveau – 20 Minuten
- Steinschlagschutz: Geobrugg testet Schutznetze in Walenstadt
- Steinschlag: Barriere besteht spektakulären Härtetest | Baublatt
- Zwei 4,8-Tonnen-Felsblöcke prallen in Walenstadt auf ein Schutznetz | Nau.ch
The strong public interest shows how relevant the topic of natural hazard prevention and innovative protection systems has become.
Outlook: Simulations and multi-hazard resilience
In parallel with the field trials, Geobrugg is developing computer simulations to analyse complex impact scenarios. The ROCCO line is also being tested for other natural hazards, such as falling trees in Walenstadt or shallow landslides in Japan. This is the company’s response to the increase in combined hazard events as a result of climate change.