Rockfall Protection Systems

Types of Rockfall Protection Systems

Construction of rockfall protection systems
Oregon DOT

Rockfall Protection Types

Rockfall protection can either be active or passive. The main function of rockfall protection is to prevent and control rocks and debris from falling. Nowadays, there are several products available to be used as rockfall protection systems and are widely used ​in new developments and in areas where slopes have not been completely stabilized. Rockfall protection is a somewhat of an imperfect science that will require special skill and specific installation procedures.

There is no rule-of-thumb when using rockfall protection systems, due to the atypical behavior or rocks and soil stabilization measures.

Rockfall Protection Scenario

  • Active Mitigation

Active mitigation is needed when there is a real danger of falling rocks. The designed rockfall protection systems must be capable of absorbing the impact of the falling rock and must contain it in such a way to reduce danger and to present safeguard against people and property.

  • Passive Mitigation

Passive mitigation is needed when the scenario is a preventive way of controlling rockfalls. This method is usually used ​ni areas that are not fractured or where slopes have been already worked with slope stabilization measures.

Rockfall Protection Systems

  • Hexagonal Mesh

Hexagonal mesh rockfall protection is different from gabion mesh. The hexagonal mesh is a double twisted safety net that provides greater restraint from stretching and when properly installed will allow the rock to move freely inside the mesh.

The double twist on the mesh is also a safety to ensure that the net will not fail if one wire from the mesh has been cut. Anchoring the mesh to the surface has different procedures and will depend on the soil characteristics. This method is recommended for rocks varying in size from 18 inches to 2 feet in diameter.

  • High Energy Absorption Panel

Some soil engineer experts claimed that the HEA Panel may be considered a passive intervention, as it acts after a fall and not before. HEA panels are manufactured using twisted cables. The HEA Panel is widely used on unstable slopes and areas prone to alteration. The combination of a high resistance cable with a soft steel wire makes it a perfect solution for handling large and small sized rocks. The HEA panel provides the best performance under static load and stress dissipation to the anchorage points.

  • Rockfall Soil Embankments

Soil Embankments are used as rockfall protection systems when the installation of drapery or mesh systems are impossible. Construction areas that are inaccessible or where part of the slope cannot be reached, soil embankments might provide the safety protection that you are looking for. Rockfall soil embankments built using local fill material to create a "green" embankment reducing the environmental impact of the system. This type of protection can withstand high energy impacts. The advantages of these systems are its low installation cost, minimum maintenance required and the integration of local resources with the environment.

Soil embankments use a wire mesh, evaluated by AASHTO and FHWA, that forms the facing element and the reinforcement section.