Reasonable particle size matching method for particle cushion layer without damaging geomembrane

The invention discloses a geomembrane damage-free particle cushion reasonable particle size matching method. The method comprises steps of establishing a relational expression between the allowable maximum particle size of a geomembrane particle cushion and overlying pressure by carrying out a local deformation damage test of the geomembrane under pressure on cushions with different particle sizesunder the action of water pressure; drawing a relation curve between the allowable maximum particle size of the particle cushion layer and the overlying water pressure, and determining a safety areaand a damage area of the particle size of the geomembrane particle cushion layer which is prevented from being broken by local water pressure; and determining the allowable maximum particle size of cushion particles, which are not damaged, of the geomembrane by utilizing the drawn relation curve according to the water pressure borne by the geomembrane in actual engineering, and further selecting reasonable particle size co