Blanket Hydro Ceiling In Terrain Area – Nagaland Case Study

Product – Ocean Geogrid

Quantity – 50100 sq m

Location – Nagaland

Ocean Non Wovens supplied 50100 sq m of Ocean Geogrid for works in the hill terrain of Nagaland. In steep, rain-heavy ground like this, geogrid reinforcement lets engineers build stable embankments, retaining walls and steep slopes from local soil instead of relying on massive concrete structures.

How reinforced soil works

Reinforced soil structures fall into two main groups: mechanically stabilized earth (MSE) walls and reinforced soil slopes (RSS). Both are built by placing alternating layers of reinforcement and compacted soil behind a facing. The soil carries compression, the reinforcement carries tension, and together they act as one composite block that resists lateral earth pressure. The idea is old: tree branches and straw were used to reinforce earth long before modern materials.

Modern reinforcement includes steel strips, welded steel mesh, wire mesh, geogrids and geotextile sheets. A facing stops soil ravelling out between reinforcement layers and makes very steep slopes and vertical walls possible. Facings include precast concrete panels, dry-cast modular blocks, welded wire mesh, wrapped-around geosynthetics and gabions. The soil placed within the reinforced zone is the reinforced fill; the soil just behind it is the retained backfill.

What matters when designing with geogrid

For a geogrid-reinforced structure, the design depends on the geogrid’s long-term tensile strength, not its short-term strength off the roll. Designers start from the ultimate tensile strength (measured to ASTM D6637 or ISO 10319) and reduce it with factors for creep, installation damage and durability (chemical and biological degradation) to arrive at the long-term design strength. Pullout resistance and the interface friction between grid and fill decide how much embedment each layer needs. In India, IRC SP:102 gives guidelines for the design and construction of reinforced soil walls.

Geogrid in soft ground: encased stone columns

Where an embankment or structure sits on soft soil, stone columns are a common ground improvement method. They raise bearing capacity in three ways. The column of crushed stone or gravel is much stiffer than the surrounding soil and carries a larger share of the load. Installing the column by vibration densifies the soil around it. And the column acts as a vertical drain, shortening drainage paths so the soft soil consolidates faster.

A stone column depends on lateral support from the surrounding soil. In very soft clay, that support is too weak and the column bulges outward under load. Wrapping the column in geogrid or geotextile supplies the missing confinement: it stiffens the column, increases its load capacity and reduces settlement. Encasement is most effective in end-bearing columns that reach a firm stratum. In floating columns, which stop within the soft layer, the lower part of the column carries less load and the encasement there contributes less.

For more reinforcement and slope projects, see our case studies.