What are geotextiles designed to prevent the movement of back-fill materials while permitting water to pass through?

Filter fabrics are specifically engineered geotextiles that serve the purpose of preventing the movement of backfill materials while allowing water to flow through. Their primary function is to maintain soil structure by filtering out fine particles from soil, which can infiltrate and clog drainage systems. This characteristic is essential in construction and civil engineering, particularly in areas like roadways, embankments, and retaining walls, where drainage needs to be managed effectively to prevent erosion and ensure the stability of soil structures.

Filter fabrics provide a crucial balance; they protect the integrity of backfill material and surrounding soil while ensuring that water can move freely, thus preventing water buildup that could lead to structural failure. Their use is fundamental in reinforcing the longevity and functionality of various applications in civil engineering and environmental protection.

Other options either focus on different functions, such as providing structural support or sealing against water intrusion, which do not meet the specified requirement of restricting soil movement while allowing water to pass through.