Geotextiles and Geogrids for Soil Reinforcement
topic
Reinforcement geosynthetics increase the tensile strength and stiffness of soil mass to construct steeper embankment slopes, mechanically stabilised earth (MSE) retaining walls, basal reinforced embankments over soft ground, and sub-base reinforcement for roads. Woven PET high-tensile geotextiles (200–1,200 g/m², tensile strength 50–1,200 kN/m at ≤10% strain per ISO 10319, junction strength >90% of rib strength) and extruded HDPE or PP geogrids (uniaxial: tensile strength 30–1,200 kN/m; biaxial: 10–80 kN/m in both directions) are principal reinforcement products. MSE retaining walls (height 3–20 m) using geogrid reinforcement at 0.3–0.6 m vertical spacing require design tensile strength (Td = Tult/RF) where reduction factors account for creep (RF_CR 1.4–3.0 for PET, 2.5–5.0 for HDPE), installation damage (RF_ID 1.05–1.30), and durability (RF_D 1.05–1.50). PET geogrid creep strain at 40% UTS over 120 years is 3–6% versus 20–35% for HDPE — PET preferred for permanent walls. Basal reinforced embankments over soft clay use geogrid tensile strength of 100–400 kN/m to span between pile caps, reducing differential settlement by 60–80%. Global geogrid market exceeds $1.6 billion.
Role
Geosynthetic reinforcement enables construction of steep slopes, tall retaining walls, and embankments over soft ground that would be geotechnically unstable without reinforcement, reducing required wall footprint by 30–50% and enabling infrastructure development on previously unbuildable marginal land.