PP Staple Fiber Geotextile：Anti‑Seepage Project for Urban Municipal Utility Tunnel
Anti‑Seepage Project for Urban Municipal Utility Tunnel (PP Staple Fiber Geotextile)
Ⅰ. Project Overview
This urban underground comprehensive utility tunnel stretches 3.2 km in total length. It features a high groundwater level and highly corrosive soil, requiring a Grade‑1 waterproofing standard.
250 g/㎡ polypropylene staple fiber geotextile is adopted as both a waterproof protective layer and a filtration layer.
Ⅱ. Application Details
The side walls and base slab of the utility tunnel foundation pit are cleaned and leveled before geotextile laying.
The geotextile is laid outside the waterproof layer to separate backfill soil from the anti‑seepage structure.
Full coverage is implemented on side walls, base slab and top slab with firm overlaps, free of wrinkles and sagging.
Combined with blind drainage pipes, the geotextile guides seepage water out of the utility tunnel in an orderly manner.
Ⅲ. Main Functions
- Resists corrosion, acids and alkalis, adapting to complex underground soil‑water environments
- Prevents backfill soil particles from entering the waterproof layer and blocking drainage systems
- Buffers soil pressure to protect the anti‑seepage layer
- Enhances the stability of the overall anti‑seepage system
Ⅳ. Implementation Results
No leakage has occurred since the utility tunnel was put into service, with smooth drainage. Underground soil‑water corrosion has minimal impact on the structure, fully meeting municipal engineering application standards.
