Define portal frame column bases

You can define each base in your frame as being pinned, fixed or spring and give the associated details on the Bases page of the Portal Frame dialog box.

Define base levels

Select the Bases page.
Select a base and adjust the Level as required.

Define a pinned base

Select the Bases page.
Select a base and set the Fixity Type to Pinned.

Define a spring base - (Ultimate Limit State)

Select the Bases page.
Select a base and set the Fixity Type to Spring.
You will see the at Ultimate Limit State (ULS) stiffnesses become available for editing.
For the vertical and horizontal directions pick Restrained or pick Stiffness and enter a value which models the movement of the base in that direction.
For the rotational direction pick Free, or pick Stiffness and enter a value which models the rotational characteristics of the base.
If you want to limit the ULS moment capacity of the base to less than 100% of that of the column to which it is connected, or to a specific value if site conditions necessitate this, then pick the appropriate Capacity option and enter the requisite value.
CAUTION: If you specify the Moment capacity your base must be able to provide this capacity at the Ultimate Limit State.

Define a spring base - (Serviceability Limit State)

You are only required to define spring SLS properties if you intend to export the frame to Tekla Portal Frame Designer for design.

To define the Serviceability Limit State (SLS) stiffnesses, select the Enhanced view check box.
You will see the at Serviceability Limit State (SLS) and Stability stiffnesses become available for editing.
For the SLS vertical and horizontal directions pick Restrained or pick Stiffness and enter a value which models the movement of the base in that direction.
For the SLS rotational direction pick Free, or pick Stiffness and enter a value which models the rotational characteristics of the base.

Define a spring base (for the P292 Stability condition)

You are only required to define spring stability properties if you intend to export the frame to Tekla Portal Frame Designer for design.

To define the stiffnesses for the P292 Stability check, ensure the Enhanced view check box is selected.
The vertical and horizontal directions are ignored for this check. They are shown to keep the dialog layout similar between pages.
For the Stability rotational direction pick , Stiffness and enter a value which models the rotational characteristics of the base, or pick Free if the base has no rotational stiffness.
The rotational capacity of the base is set at the nominal value specified for this check. This is 1% and you can not change this. However the stiffnesses and rotational values are compared with those set on the ULS page, and where the value on that page is greater than the one set here, then the larger value will be used in the P292 check.
Example: If you have Restrained set in the ULS row and you enter a value of 1000 kNm/ rad here, then the larger value from the ULS row will be used. If you have a percentage capacity of 10% set on the ULS row, then this will be used rather than the default value of 1% set on this row.

Copy details for a base

Select the line for the base you want to copy and then click Copy... to see the Copy Base dialog.
Select the target bases and then click OK to perform the copy.