1. Material Inspection & Storage
Quality Check: Verify geotextile specifications (weight, tensile strength, CBR puncture resistance) per project requirements (e.g., ASTM D4632, GB/T 17639-2008).
Storage: Keep rolls dry, covered, and elevated off the ground to prevent moisture absorption or UV degradation.
2. Subgrade Preparation
Leveling: Remove rocks, roots, and sharp debris; compact subgrade to ≥90% density.
Soft Soil Treatment: Lay a 30–50 cm sand/gravel cushion layer if the foundation is weak.
Slope Grading: For slopes steeper than 1:2, consider terracing or erosion control mats.
3. Installation Process
Unrolling: Deploy rolls along the design alignment with minimal wrinkles. Use manual labor or mechanical spreaders for large areas.
Overlap Requirements:
Horizontal Applications: 50–100 cm overlap (adjust for high-stress zones).
Vertical/Slope Applications: 100–150 cm overlap, secured with pins every 1–1.5 m.
Seaming Methods:
Thermal Bonding: Hot wedge welder (temperature: 300–400°C) for waterproof projects.
Sewing: Use double-thread, UV-resistant polyester thread (stitch spacing: ≤5 mm).
4. Anchoring & Protection
Edge Fixing: Secure with galvanized U-pins (20–30 cm spacing) or sandbags.
Temporary Cover: If backfilling is delayed, cover with ≥20 cm soil to block UV rays.
5. Backfilling & Compaction
Layer Thickness: Initial fill ≤30 cm (fine-grained soil); use lightweight machinery.
Compaction: Rollers ≤8 tons; avoid sharp turns to prevent fabric displacement.
6. Quality Control
Seam Testing: Conduct peel tests (AST D7238) or water permeability tests.
Damage Repair: Patch holes/cuts with overlapping geotextile patches (min. 30 cm beyond damage).
7. Safety & Environmental Notes
Worker Protection: Wear gloves/masks when cutting/seaming to avoid fiber inhalation.
UV Exposure Limit: Max 7 days unprotected (per ASTM D4355).
Key Standards Reference
ASTM D5261 – Geotextile tensile strength.
ISO 10319 – Wide-width strip test.
GB/T 17639-2008 – Chinese standard for filament PP geotextiles.
For slope stabilization or landfill lining, consult design-specific protocols (e.g., overlap adjustments, seaming frequency). Let me know if you need further details!
