Geosynthetic Reinforced Soil (GRS) Walls

4Geosynthetics Reinforcement

The concept of reinforced soil originated at least 6,000 to 7,000 years ago. Natural materials such as reeds, twigs, cotton, jute, straw, wood, etc. were first used as tensile inclusion in soil to construct ziggurats, dwellings, roadways, and even the Great Wall of China (Jones, 1985). A common problem for using natural materials as reinforcement in earthwork construction is with biodegradation of these materials due to microorganisms. With the advent of polymers in the early 20th century, a more stable and durable engineered material became available as tensile inclusion for earthwork construction. When properly formulated, polymers with half‐lives of hundreds of years or more can be stable even under harsh environments.

The term geosynthetics refers to polymeric materials that are manufactured and used to help solve civil engineering problems. As proclaimed by Robert M. Koerner, founder of the Geosynthetic Research Institute, “Geosynthetics are bona fide engineering materials and must be treated as such.”

In this chapter, we shall discuss the engineering behavior and properties of geosynthetics that are relevant to the analysis and design of GRS walls, including (i) load–deformation behavior, (ii) creep and relaxation behavior, (iii) soil–geosynthetic interface behavior, and (iv) hydraulic properties. We shall also discuss the advantages and disadvantages of using geosynthetics as reinforcement.

4.1 Geosynthetics as Reinforcement

The American ...