Multiple zone, high-capacity geo-composite drainage structures and methods suitable for high friction angle applications

Numerous permutations of high-friction void-maintaining membrane laminates are provided. Laminates of the invention are particularly useful for providing high performance drainage within installations having a high slope component. Void-maintaining laminates of the invention comprise flow zones of void spaces which are typically interconnected, and constructed and arranged so that the flow zones provide desirable paths for the egress of drainage fluids. The laminates advantageously include also high-friction zones which are typically interspersed between the flow zones such that the laminates are useful to provide drainage in installations of high incline angles. Laminates of the present invention provide both desired resistance to movement, that is, increased shear resistance, and flow capacity increases of from 25-100% when compared with conventional laminates.