As indicated above, the finite element model for each story extends approximately one story above and below the current level. For walls this is always true and the program will provide a translational restraint at the top and bottom of the walls above and below the current story respectively.

For columns, the program provides restraints for each axis where it is braced at the story above or below the story being analyzed. To determine the levels at which a column is braced above or below a particular story the program uses the criteria specified by the user in the Criteria-Bracing dialog box (see Section 2.5.6). A column is also assumed braced at a level if the orientation or the material type changes from one level to the next.

Where a column is braced it will be assigned a rotational and translational boundary restraint per ACI318-02 Section 8.8.3, BS8110 3.2.1. That is, where an axis of a column is braced it is assigned a translational restraint in the direction of the column axis, and a rotational restraint that will prohibit rotation of the column in the plane of the restraint. Internally the program provides fixity in the appropriate node local axes and rotates the node to align with the column orientation. The illustration below indicates the column axis that is restrained at the level above the story being analyzed, where a beam braces the column in axis 2. As noted a translational restraint will be provided in the direction of axis 2 and a rotational restraint will prevent rotation about axis 3.

The program also provides a vertical restraint under all walls and columns at the story below the current story being analyzed. The hanging columns however are restrained at the story above. The columns (and walls) are also restrained to prevent rotation about their own vertical axis at these levels. This restraint is provided irrespective of the story at which the column is braced against laterally.

Following the analysis the user can view the location that the program applied rotational and translational restraints by viewing the Finite element Model for a particular story (see Section 2.7.2)

For gravity non-concrete columns the program will also assume the columns are restrained against translation and rotation above and below the story, (the bottom of the column above the story being analyzed will be pinned against bending). Gravity non-concrete columns extend to the story (above or below the story being analyzed) at which they are braced in each axis.