Hawaii HDOT Geotextile Fabrics

Solmax DOT Standard Specification Product Chart (click image to expand)

Hawaii HDOT  - Geotextile Uses

Hawaii’s roads, airports, and harbors sit on complex ground: porous coral sands near the coast, residual volcanic silts and clays upslope, cinders and weathered basalts, and fills that can become waterlogged during kona storms or intense trade-wind showers. Add steep terrain, flashier streams, coastal surge, and high UV exposure, and you get subgrades that can rut, pump, scour, or lose fines. Geotextiles are the quiet engineering layer that keeps these systems working.

The first role is separation and stabilization. On new lanes, shoulder widenings, and runway or taxiway work, a woven geotextile is placed between weak native soils or reclaimed fills and imported aggregate. It prevents fines from migrating up into the base under traffic, spreads load, and preserves base thickness—especially valuable on saturated coastal sands and in areas where construction traffic must operate over marginal subgrade. On very soft ground, crews roll out fabric to create a working platform so haul trucks and pavers don’t punch through; in extreme cases, it may be paired with geogrid for added stiffness.

Because water drives many failures in the tropics, filtration and drainage are constant priorities. Nonwoven geotextiles line underdrain trenches, wrap perforated pipe, and separate drainage stone from surrounding soils behind retaining walls, abutments, and wingwalls. Matching apparent opening size and permittivity to local soils—clean coral sands along shorelines versus finer volcanic silts mauka—lets water move freely while fines stay put, reducing clogged outlets, wet shoulders, and base softening after heavy rain.

Where flow concentrates—culverts, storm outfalls, streams, and coastal works—geotextiles serve as riprap underlayment for rock slope protection and scour aprons. A robust nonwoven filter is placed on the prepared subgrade before armor stone. It prevents soil from piping through rock voids during high velocities, tidal cycles, and hurricane-driven surges, helping the rock “lock in” and protecting embankments at bridge approaches, channel bends, revetments, and harbor edges. On energetic coasts, seams are sewn or overlapped generously and anchored to resist uplift and wave run-up.

For temporary erosion and sediment control, geotextiles appear in silt fence, inlet protection, curb socks, and check structures. They complement fiber rolls and mats by filtering flow while trapping fines—critical for stormwater compliance on steep cuts, utility trenches, and coastal work zones. At project entrances, stabilized construction exits typically include a nonwoven geotextile beneath coarse rock; the fabric spreads wheel loads and keeps stone from punching into wet soils, limiting track-out onto public roads.

In structures and earth-retaining systems, geotextiles act as joint and face filters. Mechanically stabilized earth (MSE) walls—precast panel or modular block—use strips of geotextile behind joints to keep backfill fines from migrating to the face while preserving drainage continuity. Hawaii also benefits from pavement interlayers: asphalt-impregnated nonwoven geotextile beneath overlays improves waterproofing and slows reflective cracking, helpful in hot, UV-intense conditions and frequent wetting/drying cycles.

Finally, geotextiles provide liner protection in stormwater basins, lined ditches, and containment areas. Heavy nonwoven fabrics cushion geomembranes from angular aggregate and construction traffic, reducing puncture risk and extending system life.

Good field practice ties it together: prepare subgrades smooth, avoid wrinkles, overlap or sew seams as needed, anchor with pins or initial lifts, and cover promptly to limit UV degradation. Selection is function-driven—woven for stabilization and tensile strength; nonwoven for filtration, drainage, and protection—tuned to Hawaii’s soils, hydraulics, and coastal climate.

Hawaii HDOT