North Dakota NDDOT Geotextile Fabrics

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

North Dakota NDDOT - Geotextile Uses

North Dakota projects cross glacial tills and lakebed clays in the Red River Valley, windblown sands and gravels in the west, and wide alluvial bottoms along the Missouri. Add deep freeze–thaw cycles, spring snowmelt, ice-out events, flooding, and heavy energy/ag freight, and you get subgrades that can soften, pump, rut, scour, and settle. Geotextiles are the quiet engineering layer that keeps pavements, structures, and drainage systems working.

Separation and stabilization. On new lanes, shoulder widenings, and staged construction over marginal subgrade, a woven geotextile goes between native soil and granular base. It blocks fine silts and clays from migrating into the aggregate under traffic, spreads loads, and preserves base thickness—especially valuable over saturated valley clays, thaw-weakened shoulders, and disturbed utility cuts. Where the ground is very soft, crews first roll out fabric to form a working platform; on exceptionally weak areas, it’s often paired with geogrid for added stiffness.

Filtration and drainage. Water drives many failures on the Plains. Nonwoven geotextiles line underdrain and edge-drain trenches, wrap perforated pipe, and separate drainage stone from surrounding soils behind retaining walls and backwalls. Matching apparent opening size (AOS) and permittivity to local soils—tight clays in the east versus cleaner sands and gravels out west—lets water move while fines stay put, reducing clogged outlets, wet spots, and shoulder drop-offs. In cold regions, a nonwoven over open-graded aggregate also creates a capillary break, limiting upward moisture that fuels frost heave.

Riprap underlayment and scour control. Where flows concentrate—culverts, storm outfalls, river bends, and channel linings—geotextiles serve as underlayment beneath riprap or armor stone. A tough nonwoven filter is placed on the prepared bed or slope before rock. It prevents subgrade from piping through rock voids during high velocities, drawdown, and debris-laden spring floods, helping the rock “lock in” and protecting embankments at bridge approaches and channel transitions.

Structures and MSE walls. NDDOT corridors include many mechanically stabilized earth (MSE) walls and grade separations. Geotextiles act as joint and face filters, tucked behind panel or block joints so backfill fines don’t migrate to the face while maintaining drainage continuity. The same idea applies at wingwalls, backwalls, and structural penetrations, where a filter layer keeps weeps functioning without trapping water.

Pavement interlayers. Asphalt-impregnated nonwoven geotextile beneath overlays improves waterproofing and slows reflective cracking—important where deicing chemicals, big daily thermal swings, and heavy axle loads accelerate pavement aging. On chip seals common to rural districts, paving fabrics limit water intrusion into base and subgrade, extending service life with minimal added thickness.

Temporary erosion and sediment control. Geotextiles appear in silt fence, inlet protection, curb socks, and check structures. They filter runoff while trapping fines—critical for stormwater compliance on long medians, steep approach cuts, and urban work zones. At project entrances, stabilized construction exits typically include a nonwoven geotextile beneath coarse rock; the fabric spreads wheel loads and prevents stone from punching into wet soils, reducing track-out.

Liner protection and containment. Heavy nonwoven geotextiles cushion geomembranes in stormwater basins, lined ditches, salt-shed pads, and deicing-brine or fuel-containment areas, protecting liners from puncture by angular aggregate and construction traffic.

Field practice. Performance hinges on basics: prepare subgrades smooth, avoid wrinkles, overlap or sew seams as required, anchor with pins or the first lift, and cover promptly to limit UV and winter weathering. Selection is function-driven—woven for stabilization and tensile capacity; nonwoven for filtration, drainage, and protection—tuned to North Dakota’s soils, hydraulics, and traffic demands.

Bottom line: on NDDOT projects, geotextile isn’t “landscape fabric.” It’s a purpose-chosen engineering layer that stabilizes soft ground, manages water and fines through harsh seasons, protects structures and channels, and stretches pavement life statewide.

North Dakota NDDOT