Geomembrane Liner Installation Guide

‌I. Pre-Installation Preparation‌

‌1. Surface Preparation

• Compact subgrade to ≥90% Proctor density
• Remove all debris >20mm (stones, metal objects)
• Excavate 40cm×40cm anchor trenches along perimeter

‌II. Deployment Procedures‌

‌1. Layout & Cutting‌

• Unroll geomembrane on clean area
• Cut to designed shapes with 1-4% slack allowance

‌2. Placement Protocol

• Minimize seams using T-seam pattern
• Secure exposed edges immediately with sandbags
• Maintain wrinkle-free placement

‌3. Weather Constraints

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III. Welding Specifications

‌1. Thermal Fusion Welding

• 15cm overlap minimum
• Pre-clean surfaces with approved solvents

‌2. Extrusion Welding

• 7.5cm overlap minimum
• Bevel edges at 45° (0.5mm depth)
• Use virgin resin welding rods

‌3. Slope Welding Technique‌

1. Weld vertically down slopes
2. Anchor membrane at platforms
3. Post-weld sandbag anchoring

‌IV. Critical Quality Control‌

‌1. Defect Repair Protocol

• ≤6mm holes: Extrusion repair
• 6mm holes: Circular patch (min. 15cm overlap)
• All repairs require nondestructive testing (NDT)

‌2. Anchoring Requirements

• U-shaped trench configuration
• Secure with sandbags or concrete

‌3. Protection Measures‌

• Install geotextile cushion layer immediately
• Cover with granular fill or concrete

‌Safety & Compliance Directives‌

1. ‌Access Control‌: Permit-only personnel in work zones
2. ‌Footwear‌: Non-spiked shoes mandatory
3. ‌Material Handling‌: No dragging/dropping of rolls
4. ‌Welding QC‌:
   • Continuous speed monitoring
   • Destructive testing every 500m

Key Technical Terms: HDPE geomembrane, thermal fusion welding, extrusion welding, nondestructive testing (NDT), anchor trench