1. Significance of Metro Anti-Seepage Engineering
China’s urban rail transit has expanded rapidly, with metro construction advancing swiftly. As most metro lines are deeply buried underground, stations and tunnels face dual impacts from groundwater and surface precipitation. The effectiveness of waterproofing and anti-seepage measures directly influences construction safety and long-term operations. In cities with challenging hydrogeological conditions, material selection for anti-seepage is paramount. Research on metro waterproofing technology is thus crucial for ensuring project safety, progress, and quality.
2. Material Selection for Metro Anti-Seepage Engineering
2.1 Polymer Waterproof Membranes (PE/EVA/ECB waterproof sheets, Hongxiang Patent: ZL200810159331.4)
- Product Description: Manufactured from specially formulated virgin resin via flat extrusion, offering waterproof/anti-seepage functions.
- Features:
✅ High elasticity, flexibility, and low-temperature flexibility;
✅ Excellent impermeability and barrier properties;
✅ Strong adhesion, chemical/weather resistance, and easy installation. - Applications: Tunnels, metros, basements, roofs; ideal for vault interiors.
2.2 Polyvinyl Chloride (PVC) Waterproof Membranes
- Product Description: High-quality polymer sheets made from PVC resin blended with plasticizers, stabilizers, and UV inhibitors.
- Features:
✅ Long service life, minimal thermal shrinkage;
✅ Superior low-temperature flexibility and adaptability to temperature changes;
✅ Eco-friendly, weldable seams for high-strength joints. - Applications: Underground works, building roofs, flooring moisture barriers, reservoirs.
2.3 Nonwoven Geotextiles
- Product Description: Polypropylene/polyester staple fibers processed into nonwoven fabrics for filtration, drainage, and separation.
- Features:
✅ Flexibility, corrosion/chemical resistance;
✅ Permeable, filtration-capable, and easy to install. - Applications: Protective/drainage layers in metro structural waterproofing systems.
2.4 Bentonite Waterproof Blankets
- Product Description: Natural sodium bentonite laminated between geotextiles to combine hydraulic sealing with geosynthetic properties.
- Features:
✅ Water-activated swelling for dense sealing;
✅ Durable, eco-friendly, and multifunctional (separation/reinforcement). - Applications: Metro tunnels, building foundations, roof water tanks.
2.5 Plastic Drainage Boards
- Product Description: HDPE/EVA/EPS-based boards with molded 3D protrusions for fluid/gas drainage.
- Features:
✅ Creates架空层 (void spaces) for drainage/venting;
✅ Sound/vibration insulation. - Applications: Tunnel waterproofing, underground systems, green roofs.