Geotextile Tunnel Anti-Seepage Construction

Introduction

Geotextiles are widely used in tunnel engineering for anti-seepage, drainage, and reinforcement purposes. They effectively prevent water infiltration, enhance structural stability, and prolong the service life of tunnels. This article discusses the key aspects of geotextile application in tunnel anti-seepage construction, including material selection, construction techniques, and quality control.

Material Selection

1. Type of Geotextile – Non-woven geotextiles are commonly used due to their excellent filtration and drainage properties. Woven geotextiles may be selected for high-strength requirements.

2. Permeability – The geotextile should have appropriate permeability to allow water drainage while preventing soil particle migration.

3. Durability – The material must resist chemical corrosion, UV degradation, and mechanical damage during installation and service.

Construction Process

1. Surface Preparation

• Clean the tunnel lining surface to remove debris, sharp protrusions, and loose materials.

• Repair cracks and uneven areas to ensure a smooth substrate.

2. Geotextile Installation

• Unroll the geotextile along the tunnel wall, ensuring proper overlap (typically 30–50 cm) between adjacent sheets.

• Secure the geotextile using mechanical fasteners or adhesive bonding to prevent displacement.

3. Drainage Layer Integration

• Install a drainage composite layer (e.g., geotextile-geomembrane-geotextile) if additional waterproofing is required.

• Connect drainage pipes to direct seepage water to collection systems.

4. Protection Layer Application

• Cover the geotextile with a protective layer (e.g., shotcrete or precast panels) to prevent damage during backfilling or secondary lining construction.

Quality Control

1. Inspection of Materials – Verify geotextile specifications (thickness, tensile strength, permeability) before installation.

2. Seam Integrity – Ensure proper overlapping and sealing to prevent leakage.

3. Post-Installation Testing – Conduct water pressure tests and visual inspections to confirm anti-seepage effectiveness.

Conclusion

Geotextile-based anti-seepage systems are an efficient solution for tunnel waterproofing. Proper material selection, careful installation, and strict quality control are essential to ensure long-term performance and tunnel safety.

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