Which term is used to describe the method of preventing movement of backfill materials while allowing water to pass?

The method of preventing movement of backfill materials while allowing water to pass is best described by the term "Geotextiles." These are permeable fabrics used in conjunction with soil or rock to facilitate drainage while serving as a barrier to prevent the migration of soil particles. Geotextiles allow water to flow through them easily, which helps in maintaining the stability of the backfill while protecting the underlying soil from erosion or clogging.

The use of geotextiles is essential in various civil engineering applications, such as road construction, slope stabilization, and erosion control. By preventing the movement of soil particles, geotextiles help maintain the integrity of structures and ensure proper drainage, which is crucial in preventing water-related issues.

In contrast, drainage systems specifically focus on managing water flow, while stabilizing agents are materials added to soil to enhance its strength and load-bearing capacity. Retaining walls, on the other hand, provide structural support to hold back soil but do not inherently allow for the passage of water in the same way that geotextiles do.