Vermont VTRANS Geotextile Fabrics

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

Vermont VTRANS - Geotextile Uses

Vermont projects span glacial tills and varved clays in the Champlain Valley, steep Green Mountain corridors, alluvial floodplains, and river valleys that can rise fast during spring snowmelt and fall rainstorms. Add long freeze–thaw seasons, ice-out events, steep grades, and deicing salts, and you get subgrades that can soften, pump fines, rut, scour, and settle. Geotextiles are the quiet engineering layer that helps pavements, structures, and drainage systems keep performing.

Separation and stabilization. On new lanes, shoulder widenings, and rehab work, crews place a woven geotextile between native soil and granular base. The fabric blocks fine silts and clays from migrating into the aggregate under traffic, spreads wheel loads, and preserves base thickness—especially helpful over thaw-weakened tills, wet valley bottoms, and utility cuts. Where subgrades are very soft or saturated, geotextile often goes down first as a working platform so haul trucks and pavers don’t punch through. On exceptionally weak or variable ground, it’s paired with a geogrid to add stiffness and speed construction.

Filtration and drainage. Water drives many failures in Vermont. Nonwoven geotextiles line underdrain and edge-drain trenches, wrap perforated pipe, and separate drainage stone from surrounding soils behind retaining walls and backwalls. Choosing the right pore size and permittivity lets water move while fines stay put, reducing clogged outlets, wet spots, and shoulder drop-offs. In freeze–thaw zones, a nonwoven over open-graded aggregate also forms a capillary break, limiting upward moisture that fuels frost heave and weakens base layers in winter.

Riprap underlayment and river repairs. Where flows concentrate—culverts, storm outfalls, river bends, and high-energy mountain streams—geotextiles serve as underlayment beneath riprap or armor stone. A robust nonwoven filter goes on the prepared bed or slope before rock placement. It prevents subgrade soils from piping through rock voids during high velocities, rapid drawdown, and debris-laden floods, helping the armor “lock in” and protecting embankments at bridge approaches and channel transitions. On long or steep reaches, seams are overlapped generously or sewn and anchored to stay continuous under shifting hydraulics.

Structures and MSE walls. VTrans corridors include many mechanically stabilized earth (MSE) walls and grade separations where right-of-way is tight. 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 concept applies at wingwalls, backwalls, and around penetrations, keeping weeps functioning without trapping water and preventing staining at facings.

Pavement interlayers. Asphalt-impregnated nonwoven geotextile beneath overlays improves waterproofing and slows reflective cracking—important where thermal cycling, studded tires in higher elevations, and deicing chemicals accelerate pavement aging. On chip seals used for preservation, paving fabrics limit water intrusion into base and subgrade with minimal added thickness.

Temporary erosion and sediment control. During construction, geotextiles appear in silt fence, inlet protection, curb socks, and check structures. They filter runoff while trapping fines—critical for stormwater compliance on steep cuts, long medians, and in sensitive cold-water watersheds. At project entrances, stabilized construction exits typically include a nonwoven geotextile beneath coarse rock to spread wheel loads and keep stone from punching into wet soils, reducing track-out.

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

Field practice. Performance hinges on basics: prepare subgrades smooth, avoid wrinkles, use proper overlaps or sewn seams, anchor with pins or the first lift, and cover promptly to protect from weathering. Selection is function-driven—woven for stabilization and tensile capacity; nonwoven for filtration, drainage, and protection—tuned to Vermont’s soils, hydraulics, and traffic demands.

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

Vermont VTRANS