Abstract: A method for building a road bed by providing a plurality of vaulted structures located at a road bed site. A first layer of concrete is applied on the structures for reinforcing the structures. The structures can be comprised of a profiled steel plate or a sheet metal mesh. They may have reinforcement braces comprised of troughs or corrugations provided on an outer surface of the structures which receive the first layer of concrete. The first layer of concrete is allowed to set before a second layer of concrete is applied to the structures and to the first layer to form a concrete casing.