A small town after debris flow passed.

Debris Flow Barrier

Debris Flow Barrier Provides Maximum Energy Absorption Against Disaster

Debris flows, sometimes referred to as mudslides, mudflows or debris avalanches, are fast-moving landslides that occur in a wide variety of environments throughout the world. They are particularly dangerous to life and property because they move quickly, destroy objects in their paths, and often strike without warning. Therefore, establishing debris flow barrier within the anticipated path of the debris flow or shallow landslide is essential. It is generally established in natural valleys, gullies, channels and chutes, perpendicular to the flow direction.

What is debris flow barrier?

Debris flow barrier, also known as debris flow fence, is typically a rigid structure that is designed to mitigate the impact of debris flow and help control the destructive power of the event by limiting velocity and erosive potential.

Much like the rockfall barrier, it is required to be capable of retaining destructive objects, controlling the moving debris flows and mitigating the impact of debris flow to infrastructure and residential areas. It commonly adopts a combination of ring net system and Rockcon/hexagonal mesh to provide better impact resistant performance. Ring net system is generally positioned in natural valleys, gullies, channels and chutes, perpendicular to the flow direction. Ring net system is commonly used to block large stones, floating timbers and large destructive objects while Rockcon/hexagonal mesh is designed to block small floating items to allow only flowing water passing through. As a result, destructive objects no matter big or small are retained by debris flow barrier, thereby reducing their impact to downstream infrastructure and residential area.

Debris flows are retained by the debris flow barrier.

Ring net system is a kind of flexible protection system that has the highest strengths of any mesh in the rockfall system range. Due to its highest strength and maximum energy absorption capacity, it commonly used as debris flow barrier. It generally consists of ring net, steel posts, brake rings, rope anchors and support ropes. Ring net consists of various interlinked steel rings between 5 and 19 spirals are bundled together. All steel rings are made of high tensile steel wire with a tensile strength of 1770 N/mm2 and two ends of lap length not less than 100 mm. This unique structure gives the ring net great buffering performance through its deformation. Upon impact by the debris flow, the ring net deforms greatly with brake rings tightening and absorbing the impact energy. As the ring net has a large mesh opening and cannot stop the movement of small rocks, it generally works with Rockcon® mesh or hexagonal mesh to increase the overall performance of the ring net system. In narrow valleys, the system can be anchored directly to the wall surface of the valley without posts, however, in wider valleys, steel posts are required for better anchoring and impact resistance performance.