Book excerpt: When it comes to using reinforcements to grant better mechanical performance to soils, geosynthetics, one of the newest groups of building materials, have become mandatory in almost all works of infrastructure, draining applications, waterproofing, paving, erosion control and soil reinforcement. This volume presents the basic mechanisms associated with soil-reinforcement interaction and a rational design method for reinforced soil-retaining structures. Concepts are described with didactic and theoretical rigor, fulfilling the practical needs of engineers involved in the design, construction and inspection of reinforced soil structures.