... into dimple shape.On top of it, there is filtration geotextile. Shenghong composite drainage board is a dimple geomembrane, ... deformation. On the top of the dimples, there is filtration geotextile to make sure the drainage channel runing well without ... upper or bottom layer of building foundation, basement wall, bedding filtration and heat insulation 4)Traffic engineering: highway, railway basement, ...