Tunnel leakage corrodes linings and damages equipment; repairs cost far more than prevention. Issues: rough support surfaces puncturing sheets, undrained inflows building pressure, poorly sealed welds and disc points, and unstable cold-season welding.
Tunnel & Underground Works: Standard build-up: dress the primary support and drain inflows first; hang 300-400 g/m² geotextile cushion; fix welding discs quincunx-style (arch ≤0.8m, walls ≤1.2m); hang 1.2-2.0mm EVA (or HDPE in aggressive water) with 10-15% slack; double-seam weld laps ≥100mm and air-test at 0.15-0.25 MPa; patch and retest defects; add behind-lining drainage composites where designed.
Tunnel leakage corrodes linings and damages equipment; repairs cost far more than prevention. Issues: rough support surfaces puncturing sheets, undrained inflows building pressure, poorly sealed welds and disc points, and unstable cold-season welding.
| Location | Recommended material | Reason |
|---|---|---|
| Waterproof sheet | 1.2-2.0mm EVA / HDPE board | EVA mainstream; HDPE for aggressive water |
| Cushion | 300-400 g/m² filament geotextile | Puncture protection |
| Fixings | Welding discs + nails | Quincunx per spacing |
| Back drainage | Composite drainage net 3-5mm | Relieves water pressure |
| Details | Patches + extrusion rods + sealant | Joints and repairs |
2022Support dressed and inflows drained, 400 g/m² geotextile cushion hung, 1.5mm EVA board fixed on quincunx discs (arch 0.8m), double-seam welded laps air-tested, defects patched and retested before secondary lining.
View project details ›EVA for most tunnels (flexible, cold-tolerant); HDPE where groundwater is chemically aggressive.
Arch ≤0.8m, walls ≤1.2m quincunx; densify in broken rock or high inflow.
Dezhou Yurun Geosynthetics Co., Ltd. is a source manufacturer of geosynthetic anti-seepage materials, located in the geosynthetic industrial cluster of Lingcheng District, Dezhou City, Shandong Province, China. We supply HDPE geomembrane, pond liners, composite geomembrane, filament and staple geotextile, tunnel waterproof board, composite drainage net, sodium bentonite GCL, ecological bags and cement blanket to projects across China and overseas.
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Same number: 13105341718
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HDPE geomembrane · pond liner · composite geomembrane · geotextile · GCL · drainage net · geobag · cement blanket · tunnel board
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