For the study of the behaviour and design of geotechnical structures subjected to medium-energy lateral impact loads (1 MJ, equivalent to a 3-tonne mass propelled at 100 km/h), the RRO Laboratory has a hydraulic catapult located on the Gustave Eiffel University site in Bron. This equipment, which enables instrumented horizontal impact tests to be carried out, complements the block drop test facility at Gustave Eiffel University in Montagnole, although the latter delivers energy on a scale approximately 13 times greater.

The equipment is housed in a covered building 80 m long. ‘Free-wheeling’ impactors are propelled and released, either towards an indoor impact area featuring a rigid reaction wall, or towards a 1,500 m² outdoor impact area where the geotechnical structures to be tested are built to full scale (various reinforced earth berm structures, retaining walls, pylon foundations, etc.).

Propulsion is provided by a towing carriage attached to a cable running in a closed loop, driven by hydraulic motors. A real-time control system enables a specified target speed to be reached at the end of a specified towing distance prior to release (maximum 80 m).

The RRO Laboratory develops highly rigid, self-propelled test rigs (trolleys) for its research, equipped with an impact device capable of simulating a collision between the structure under test and a solid with an apparent density similar to that of rock, when studying structures subjected to rockfall impacts.