• After defining the vault in the required position and geometry in your project, activate the Set Vault Restraints command in the Vault auxiliary toolbar.

  • The Set Boundary Conditions dialog will open.

  • In the dialog that opens, after marking the boundary conditions for solution with building system, make your arrangement so that only the option/options that are supported on each side of the vault will remain active.

If you want to solve the vault element with the structure, it would be a better solution to select the Use semi rigid diaphragm option from the Analysis Settings dialog, General tab.