1. Structural Form and Water Flow Mechanism

• Drainage Geonet:
Features a three-dimensional net-like structure. It is manufactured from high-density polyethylene (HDPE) through extrusion, forming continuous intersecting ribs (commonly available in double-rib or triple-rib designs). Its key advantage is the creation of “open flow channels,” allowing water to move continuously through internal voids with very low flow resistance.

• Drainage Board:
Features a two-dimensional sheet structure. It typically consists of a flat base layer with continuous conical studs or column-shaped dimples. Water mainly flows through the gaps between the raised studs or the space beneath the board, creating a “point support” drainage system.

2. Compressive Strength and Deformation Characteristics

• Drainage Geonet:
Provides excellent compressive resistance. In particular, composite drainage geonets with triple-rib structures can maintain their internal drainage channels even under overburden pressures exceeding 800 kPa, with minimal reduction in drainage performance. They are suitable for deep burial applications.

• Drainage Board:
Has relatively lower compressive resistance. Although individual dimples may have high stiffness, the structure can experience lateral displacement or compression under high pressure, causing drainage channels to become blocked. It is generally used in shallow cover applications, such as basement garage roofs, or in areas without heavy structural loading.

3. Drainage Efficiency and Functional Focus

• Drainage Geonet:
Designed for high-volume water conveyance. With a very high void ratio (up to over 90%), its primary function is to rapidly transport large amounts of liquid, such as landfill leachate or roadway meltwater.

• Drainage Board:
Provides both water storage and drainage functions. In addition to drainage, many models (such as storage-drainage boards) are designed with recessed cavities to retain a certain amount of water for plant root absorption. They are also widely used for moisture protection and root barrier applications.