Buried weak layer

slope soft and weak layer

underlying weak layer

weak layer

Adhesive　layer　material

air permeability of material layer

cushion layer material

double layer material

height of material layer

layer material

Layer-Material

material layer

material layer comminution

material layer thickness

material layer through-hole devices

Packing material layer

piles the material layer

preparation of cushion layer material

pressure difference of material layer

sacrificial layer material