Aplicação de materiais geossintéticos em aterros sanitários modernos - Pontos-chave de projeto e construção

I. Key Design and Construction Points

Material Selection and Specifications: HDPE Geomembrane: Strict selection of resin raw materials (virgin material), carbon black content , thickness, various mechanical indicators (tensile, tear, puncture), stress crack resistance performance.

GCL: GCL: Bentonite quality, bentonite quantity per unit area, hydration expansion property, permeability, shear strength, and interface friction angle with upper and lower materials.

Geosynthetic Composite Drainage Net: Hydraulic Conductivity, Compressive Strength, Soil Retention and Permeability of Geotextile (to prevent clogging), Interface Friction Angle.

Geotextile: Mass per unit area, thickness, mechanical strength, equivalent aperture (O90/O95), permeability, and clogging resistance.

Slope stability analysis: Landfill slopes (especially steep slopes of the bottom liner and final cover) are weak links.

Core Risk: Sliding failure along the interface caused by insufficient interface shear strength between the geomembrane (or GCL) and the upper and lower geotechnical materials (geotextile, geogrid, clay) or soil body.

Solution: Conduct a detailed limit equilibrium method or finite element method stability analysis, taking into account the friction angle and cohesion between different material interfaces . Increase surface texture (geotextile) or use reinforcement materials when necessary.

Anchoring Trench Design: Geomembranes, geotextiles, drainage nets, etc., need to be anchored around the landfill. The anchoring trench must meet the pull-out resistance requirements, and the design should include reasonable dimensions and backfill compaction degree.

Connection (Welding/Sewing): Geomembrane Welding: It is a lifeline! Each weld must undergo non-destructive testing and destructive testing (on-site sampling for shear/peel tests).

II. Long-term Performance and Monitoring

Aging: Ultraviolet radiation (during construction), heat and oxygen, and chemical substances (leachate) may cause degradation of material properties. Select anti-aging formula materials of HDPE geomembrane.

Monitoring: Leachate collection volume monitoring. Landfill gas production and composition monitoring. Surface subsidence monitoring.

Geosynthetic Membrane Leakage Monitoring System: An electrode sensor network is installed between the two layers of a double-liner system, which can accurately locate leakage points in the primary liner.

Resumo

Geosynthetic materials are indispensable ‘safety guardians’ in modern sanitary landfills.

Materials such as HDPE geosynthetic membranes, GCLs, geocomposite drainage nets, and geotextiles work together to construct efficient and reliable impermeable barriers, drainage channels, and cover systems.

Their successful application depends on scientifically rigorous design , strict material quality control, standardized and meticulous construction operations (especially welding), and comprehensive long-term monitoring.

With technological advancements, intelligent geosynthetic materials are also increasingly for applications in leakage monitoring, further enhancing the safety and intelligent management level of landfills.