A broad category of works to protect against rockfall, including barriers, nets and embankments.
Passive structures are designed to intercept or divert rocks which break free by means of localised structures, mainly positioned at the foot of slopes or rockfaces and which can be broken down into:
- Flexible rockfall barriers: lightweight, deformable structures with very strong components made from high-quality, durable materials. The structures are lightweight, simple, quick to install and maintain, meaning that they can be installed even in hard to access mountainous areas.
- Rockfall valleys and embankments: these are some of the most effective and least expensive passive protection methods currently available. The embankment consists of an wall of earth with a trapezium-shaped profile, made from coarse, loosely material taken from the excavation of the valley or available locally.
Active protection structures act at the source of the problem, preventing rocks from detaching from the rockface. The most common solutions include:
- Single or dual-twist hexagonal-mesh anchored nets: galvanised steel nets which are firmly anchored to the slope in several points and tensioned.
- Panels: combined with a hexagonal-mesh net and positioned in the most critical positions on the slope where there are the biggest volumes of rock to be secured and consolidated.
- Pinning and anchoring of blocks of rock using passive type ground anchors to tie unsafe rocks to the ground, preventing them from moving in any way.