Firstly I select a suitable tiled texture.

I then create a plane in max and add the texture to the displace function.

Then displace the plane by applying the texture.

I then add the texture to the finished model, which can be further enhanced with a normal map, if you wish.

Finally I modify the plane to create a cutting which can be lofted in the same way you would loft a viaduct or any other repeating scenery item.

Perhaps not exactly what Longbow wanted but does add some character to cuttings/cliff faces etc.
