Geomembrane, as an important geosynthetic material, is widely used in anti-seepage projects such as water conservancy projects, landfills, and road foundations. Its design principles are primarily based on the material's physical and mechanical properties, as well as the actual requirements of the project environment. Through scientific calculations and rational selection, the project's safety and durability are ensured.
Geomembrane design primarily considers its anti-seepage performance. The core indicator is the permeability coefficient, which is typically required to be in the range of 10⁻¹² to 10⁻¹⁷ cm/s to meet stringent anti-seepage requirements. High-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE) are the mainstream materials due to their excellent chemical stability and aging resistance. The long-term resistance of the material must be evaluated based on the corrosive properties of the project medium (such as sewage and landfill leachate).
Mechanical design is another key aspect. Geomembranes must withstand tension, shear, and external loads during construction, so their tensile strength, elongation, and weld strength must meet regulatory requirements. For example, HDPE geomembranes typically have a yield strength of ≥20 MPa and an elongation at break of ≥700%, ensuring resistance to cracking when the foundation deforms. Furthermore, combining the membrane with materials such as geotextiles and geogrids can enhance overall stability, optimizing interlayer bonding through friction coefficient calculations.
Environmental adaptability is equally important. Geomembranes need to resist UV rays, temperature fluctuations, and bioerosion, so carbon black antioxidants are often added. Thickness is controlled (typically 0.5 to 2.0 mm) to balance flexibility and durability. In complex terrain, finite element analysis is used to simulate stress distribution to avoid localized stress concentrations that could lead to damage.
In summary, geomembrane design requires a comprehensive understanding of materials science, mechanical calculations, and environmental engineering theory. Through precise selection and structural optimization, effective waterproofing and long-term reliability can be achieved.
