Geosynthetics for Hazard Management In the Rockfall-Prone Himalayan Mountains

Rockfall barriers and slope meshes reduce the risk to roads, railways and pilgrim routes in the Himalayas. Ocean Geosynthetics manufactures rockfall barriers that protect people and infrastructure from falling rock, boulders and snow debris on mountain slopes.

Himalayan slopes are young, steep and fragile, and they react quickly to heavy rain, snowmelt, earthquakes and road cutting. The ranges are also home to some of India’s most visited shrines: Badrinath, Kedarnath, the Amarnath cave, Gangotri and Yamunotri draw lakhs of pilgrims every year, and Muktinath, across the border in Nepal, draws many Indian pilgrims too.

The approach roads to these shrines run below steep rock faces, and rockfalls on pilgrim routes have killed people in the past. Falling rock also damages roads, bridges and old structures along the way, and the risk rises during the monsoon and the snowmelt season.

Many of these routes climb above 11700 feet (Kedarnath itself is at about 3,583 m), where access is difficult and construction seasons are short. Light, flexible protection systems that can be carried in and installed quickly are often the practical choice there.

Rockfall Barriers and how they can help:

Rockfall mitigation is a routine part of railway, highway and slope stabilization work in mountain terrain. On Himalayan slopes it needs careful design based on a site survey: slope topography, height of fall, rockfall travel distance and travel angle, and the expected size and volume of falling blocks. Together these set the energy the system must absorb, and so the type and strength of barrier.

Rockfall protection is supplied as rockfall fences, rockfall drapery and mesh nets. The right choice depends on the site, and a combination of two or more types is often the most economical solution: for example, drapery on the source zone and a fence lower down to catch what still falls.

Rockfall drapery is made of high-tensile, double twisted steel wire mesh with corrosion protection, so it can stay on an exposed slope for years in harsh weather. It resists punching by falling rock and deforms little under load. The mesh is anchored along the top of the unstable slope and hung down the face. Further anchors hold it against the slope, so loose rock and snow debris are contained under the mesh and guided down to the toe instead of bouncing onto the road.

These systems are relatively easy to install, light and strong, need modest anchor forces and are protected against corrosion, which makes them practical on remote, high-altitude Himalayan slopes.

Ocean Geosynthetics has been in the industry for over two decades and manufactures rockfall drapery, fences, mesh and rockfall nets, along with a wider range of geosynthetic products for slope and geoenvironmental projects.

For more information on our hazard mitigation products, please contact our team.