To manage surface and ground water for road network, subsurface drains are built with a permeable conduit such as corrugated plastic, geonet, tubing, tile, stone, pipe or any combination installed beneath the ground surface to collect and/or convey drainage water to an outlet.
Effective subsurface drains are essential to prevent the harmful and destructive force of uncontrolled water. Most infrastructure failures in applications such as highways, airfields, railroads, parking lots, buildings, retaining structures, mines and dams are attributed to the harmful effects of uncontrolled water.
TYPAR® Geotextile subsurface drains are simple to design and inexpensive to construct. TYPAR Geotextile filters water flowing to the drain and minimizes soil particles from passing, reducing the chance of system clogging (piping failure) and ground settlement. TYPAR geotextile are available in a wide variety of opening sizes, the appropriate grade can be selected depending on the soil particle size in critical applications.
TYPAR geotextile is recommended in all subsurface drains to provide a separator to prevent intermixing of the drainage aggregate materials with the subgrade soil and therefore protect the drainage system from clogging.
Drainage Problem without Typar Geotextile
Drainage with Typar Geotextile
- The base and side walls of the trench should be as free of irregularities as possible (holes, roots, etc.). Lay Typar® parallel to the trench and anchor the edges of the fabric.
- Do not drag the fabric in the mud. This will result in the deposit of a large amount of fine particles on the surface of Typar® thus creating an impervious film.
- Off-load the drainage aggregates carefully to avoid the fabric being dragged towards the bottom of the trench.
- Do not use over-large stones to fill up the trench. Gravel of max. size 2 cm is required to ensure good fabric-to-soil contact.
- Compact the aggregate and enclose it withTypar® before backfilling to the top of the trench.
- Overlap lengths of Typar® by at least 30 cm.