Abstract: A method of constructing a gallery in which a trench is excavated and the gallery is either constructed in or lowered into the excavation. The gallery is braced internally to withstand external loads applied. Thereafter a controlled backfill is applied around and over the gallery in such manner that with removal of the bracing the backfill acts effectively to form an arch above the gallery which together with the gallery is sufficient to support the overlying covering material up to the ground surface.