An earth overfilled arched structure includes a shallow arch spanning a clear
space. The sides of the clear space are formed by curved or straight walls. Solidified
zones of earth material (backfill or in situ) against the springs of the arch and/or
behind the walls form foundation blocks which are in intimate contact via arch
footings with the springs of the arch and/or with the upper part of the sidewalls
in such a way that the arched structure delivers most or all of its support forces
into the foundation blocks. These, due to their size and weight, transfer and spread
the support forces to the subsoil so that displacements, especially in the horizontal
directions, are minimal.
