Systems that address rockfall at the source, along the trajectory and at the target: anchored mesh, drapery mesh and flexible barriers. Energy class and system selection follow from the discontinuity sets measured on site, the block size and the trajectory results.
Systems
- Flexible barrier100 – 12,500 kJ, assessed under EAD 340059.Geobrugg, imported
- Drapery meshHexagonal double-twist wire mesh, EN 10223-3.Made by Artusa
- Ring netPanels made to size from high-strength steel rings.Made by Artusa
The problem
Rockfall is not a single accident but a process that keeps going. A block on the slope face waits already separated by intersecting discontinuity sets; weathering, freeze–thaw cycles, root wedging and joint water pressure after rain release it one day. At risk are road and railway corridors, settlements built against the toe of a slope, construction sites and power lines. The hazard arises where three components meet: the block waiting at the source, how far the slope makes it bounce, and what lies below.
The warning signs are visible to a trained eye: open joints, cracks widened by ice and roots, undercut beds, suspended blocks, the colour difference that betrays a fresh detachment, angular fragments collecting in the ditch. If the fragments at the toe are of similar size, the source is fed by one particular set. When these traces are not recorded, the design rests on assumption.
How we decide
What we measure is defined: dip and dip direction of the discontinuity sets, spacing, persistence, roughness, infill and water condition; block size distribution; slope height and mean inclination; horizontal distance to the target and the free space available. A kinematic check comes first (planar sliding, wedge, toppling); a trajectory solution then gives the distribution of energy and bounce height. In the logic of ONR 24810 the design value is taken from an upper fractile of that distribution and increased by a partial factor tied to the consequence class. Seismic action enters through the applicable national code (TBDY 2018 in Türkiye).
| Observation | Criterion | Decision |
|---|---|---|
| Large blocks detaching one by one | An unstable set exists and the source is accessible | Work at the source: anchored mesh, bolts, scaling |
| Weathered surface, small fragments | Regular slope, limited block mass | Drapery mesh, collection at the toe |
| Free space between slope and target | Energy and bounce height can be computed | Ditch or flexible barrier; class from energy, height from bounce |
| Design energy above the available classes | Narrow space, critical target | Source treatment together with a barrier, or an embankment |
| Source inaccessible, event frequency unknown | No observation record | A monitoring and measurement period first |
A barrier elongates on impact and needs room behind it; the free space is therefore measured before the energy class. Our Turkish Q&A covers where a barrier is placed and how its height is chosen.
System family
| System | When it fits | Source |
|---|---|---|
| Flexible rockfall barrier | When there is a catch distance | Geobrugg, imported |
| High-tensile anchored mesh | When the block is to be held at the source | Geobrugg, imported |
| Hexagonal double-twist wire mesh | Drapery; guiding fragments down to the toe | Made by Artusa |
| Ring net panel | Local reinforcement, made to size | Made by Artusa |
| Rock bolts, cable anchors, cable net | Load-bearing in both families | Installed by Artusa |
| Rock scaling | Before mesh and barriers | Artusa crews |
Flexible barriers are classified by full-scale impact tests. In the MEL test the system takes a single impact at its nominal energy and must hold the block; in the SEL test two consecutive impacts at one third of MEL are applied without repair in between, and the residual height is measured after both. This regime began with ETAG 027 and continues under EAD 340059; anchored mesh and drapery kits fall under EAD 230025-00-0106. The document belongs to the system as a whole: replacing a cable, a brake or a connector removes the proven behaviour.
Installation
On steep faces that machines cannot reach, experienced rope-access crews do the work; where access allows, a basket platform is used. Work at height is organised under EN 795 and EN 365.
- Scaling: bringing down loose blocks, removing roots and vegetation.
- Setting out: anchor and post-foundation axes, line axis check.
- Drilling and anchoring: length, diameter, grout volume and setting time are recorded.
- Load-bearing elements: cable network, brake elements, posts, pre-tensioning.
- Mesh laying and close-out: overlaps, clip spacing, toe detail, ID tag plate, as-built survey.
An anchor without a record is not accepted.
Acceptance and maintenance
The acceptance file collects the anchor pull-out test results (in the frame of EN 1537), as-built anchor positions and lengths, mesh overlap and connection frequency, cable pre-tension, the barrier line axis with nominal and residual height, the corrosion protection class (EN ISO 1461, EN 10244-2) and the declaration of performance.
What follows is simple: a visual inspection at least once a year and after every significant rainfall, earthquake or impact; emptying accumulated material; measuring brake activation; checking corrosion and loosening. Every line we build carries a QR-coded ID tag where these records live.
Frequently asked
- Barrier or drapery mesh? The decision starts with free space: a barrier if there is a catch distance, anchored mesh if there is none.
- Who sets the energy class? Not the catalogue. The class follows from the design block and the trajectory solution; our energy class tool (Turkish, free registration) runs the first estimate.
- A rock hit the barrier, what now? The line is closed, residual height and brake activation are measured, and the repair scope follows from those measurements.
System and product pages (Turkish)
Field record
54 projects in this family in our records, 2014–2026: Türkiye, Saudi Arabia, Oman, Iraq. Under confidentiality agreements, project and client names are not published.
Tools for this solution (Turkish)
Kinematic pre-analysisEnergy class estimateTrajectory pre-analysis