andamiaje or armazón, plataforma, tablado, andamio
Andamio or plataforma, both are correct.
Andamiaje, used by masons.
Scaffolding (n); Andamiaje (n) Scaffold (n) (for building work); Andamio (n)
To me word that you look for is TARIMA, an elevated scaffolding for musical productions, theatre or as a center piece of large meetings. In the last case the table of honor and the speakers stand is found on it.
