Column properties

Tekla Structural Designer
2021
Tekla Structural Designer

Column properties

General
Name The automatically generated name.
User Name Can be used to override the automatically generated name if required.
Group The name of the group to which the member belongs.

See: Concrete beam and column groups , Steel member design groups

Top Level Specifies the top level for the column.
Base Level Specifies the bottom level for the column.
Plane Indicates the Frame when the column has been placed in a Frame View.
Characteristic Column
Material type
  • Steel
  • Concrete
  • Timber
  • General
  • Cold formed
  • Cold rolled

Construction,

Fabrication

The available construction and fabrication options depend on the characteristic and material type selected, see Member characteristic, construction and fabrication properties
Autodesign

See: Concrete member autodesign, Steel member autodesign

Design section order

(steel only)

The design order file from which a section size will be selected.
Note: Only displayed for Autodesign
For details of managing order files, see: Manage design section orders
Select bars starting from

(concrete only)

This option controls the starting point for auto-design procedures and is therefore only displayed if Automatic design is ‘on’. It applies to both longitudinal bars and links.

• Minima (default) - removes the current arrangement and begins with the minimum allowed bar size.

• Current - the auto design commences from the current bar arrangement.

See: Concrete member autodesign, Steel member autodesign

Gravity only Controls whether the member is defined for gravity combinations only, or gravity plus lateral:
  • On = designed for gravity combinations only
  • Off = designed for gravity and lateral combinations

See: Designing individual members for gravity only

Rotation

Rotation of the column about its local x axis.
Note: For a vertical column:
  • 0° - column local y aligns with global X
  • 90° - column local y aligns with global Y
Assume extra floors supported Enter the number of extra floors supported.
Simple column

(steel only)

See: Simple columns
All stacks
Section The section size
Concrete type,

Grade/Class

(Concrete columns only)

While you can apply both normal and lightweight concrete, wall design using lightweight concrete is currently beyond scope.
Alignment (concrete only)
Major snap level,

Minor snap level,

Define the major and minor alignment of the member relative to the insertion point.
Major offset,

Minor offset

Used to offset the member from the snap point in the major and minor axis.
Face A cont. rest.,

Face C cont. rest.

(steel only)

Indicates continuous restraint to Face A and/or Face C.

See: Restraints

Releases
Fixity Top,

Fixity Bottom

  • Pinned
  • Fixed
  • Moment (pin My)
  • Moment (pin Mz)

See: Column releases

Axial load release top An axial (Fx) release is only allowed at the top of the column.
Torsional load release top,

Torsional load release bottom

Check one end only to define a torsional release.
Wind loading
Apply open structure wind load

Select this flag if you want open structure wind loads to be calculated.

See: Open structure wind loads

Shape factor, Cf The default shape factor varies according to the entity type and is taken from Model Settings > Loading > Wind Loading
Note: Default Cf factors are taken from the document ‘Wind Loads For Petrochemical And Other Industrial Facilities’ published by ASCE.
Effective area XY
Formula The default effective area formula varies according to the entity type and is taken from Model Settings > Loading > Wind Loading
Factor The factor used in the above formula can be edited if required.
Effective area XZ
Formula The default effective area formula varies according to the entity type and is taken from Model Settings > Loading > Wind Loading
Factor The factor used in the above formula can be edited if required.
Size constraints (steel only)
Max depth,

Min depth,

Max width,

Min width

Size Constraints are only applicable when Autodesign is checked. They allow you to ensure that the sections that Tekla Structural Designer proposes match any particular size constraints you may have.
Instability factor (steel only)
Prevent out of plane instability Define if out of plane stability is prevented.

See: Instability factor

Analysis & design control (concrete only)
Assume cracked

Assuming concrete sections are cracked has a direct affect on the analysis; smaller Modification Factors are applied to cracked sections causing an increase in deflection. Indirectly the design can also be affected because the sway/drift sensitivity calculations are also influenced by this assumption.

See: Cracked, partially cracked, and uncracked concrete members

Apply rigid zones Unless cleared, rigid zones are automatically created at the connection between the column and any connecting beams.
Design parameters (Eurocode only)

Permanent load ratio option

Relative humidity (RH)

Age of loading

You are required to supply a value for the permanent load ratio parameter. A default of 0.65 has been assumed, but you are advised to consider if this is appropriate and adjust as necessary.

Age of loading is the age at which loading is applied.

See: Design parameters (Eurocode only)

Confinement reinforcement (concrete only)
Provide support regions

• Checked - confinement reinforcement is designed separately in three regions.

• Cleared - the same confinement reinforcement is designed for the whole stack.

Slenderness (concrete only)

Direction 1,

Direction 2

• Braced

• Bracing

Direction 1 effective length factor,

Direction 2 effective length factor

• Calculated

• User input value

Stiffness (concrete only)
Use slab for calculation upper, lower

For the unrestrained length calculation:

• if a slab exists at a panel end, it can be ignored by unchecking the relevant box.

• If no slab exists at that end, the setting is redundant - in which case the program considers the setting at the remote end of the next panel instead.

See: Stiffness

Sway and drift checks
Merge with stack below

Columns are divided into stacks and walls are divided into panels at floor levels where members or slabs connect to the column/wall. For the purposes of Sway/Drift, Wind Drift and Seismic Drift checks only you can override the default stack/panel divisions by merging a stack/panel with a lower stack/panel. The length of the combined stack/panel is then used in the checks.

Sway/Seismic drift checks

By default all stacks of all columns are taken into account in the calculation to determine the sway sensitivity of the building. The results of this calculation being accessed from the Review toolbar.

This parameter provides a facility to exclude particular column stacks from these calculations to avoid spurious results associated with very small stack lengths. You can either clear the checkbox located under ‘All Stacks’ to exclude the entire column, or you can exclude a particular stack by clearing the checkbox located under that stack only.

Wind drift check,

Wind drift ratio

Wind drift is automatically checked against the specified limiting ratio, (which can be set differently for different columns). The results of this calculation are accessed from the Review toolbar.

If you don’t want this check to be performed you can either clear the checkbox located under ‘All Stacks’ to exclude the entire column, or you can exclude a particular stack by clearing the checkbox located under that stack only.

Nominal cover The nominal concrete cover is the distance between the surface of the reinforcement closest to the nearest concrete surface (including links and surface reinforcement where relevant) and the nearest concrete surface.
Seismic
In a seismic force resisting system

If this is the case, select the checkbox, and then specify the SFRS direction and type.

Note: Design of members in seismic force resisting systems is only supported for the ACI/AISC Head Code in the current release.

Shear demand/shear capacity ratio in Dir 1

Shear demand/shear capacity ratio in Dir 2

(ASCE 7 code only)

When working to the ASCE 7, the engineer can directly define the shear demand / capacity ratio (beta) in each direction. The default value of 1.0 could be over-conservative.

The setting is applicable to all years of the ASCE 7 code and has the following default and limits: Default = 1; Min = 0.001; Max = 10.

Utilization ratio
Apply (to autodesign) On
  • When an Autodesign is performed, the design will be incremented to achieve a utilization ratio less than the ratio limit.
Off
  • When an Autodesign is performed, the design will be incremented to achieve a utilization ratio less than 1.0.

See: Apply user defined utilization ratios

Apply (to check) On
  • When a Check is performed, the check will pass provided the utilization ratio is less than the ratio limit.
Off
  • When a Check is performed, the check will pass provided the utilization ratio is less than 1.0.
Ratio limit The utilization ratio against which the autodesign or check is performed (when applied above).
Fireproofing
Protected When members are set as 'Protected', self-weight of the members is increased by the weight of fireproofing.

See: Fire proofing

UDA

Name

Finish

Class

Phase

Note

File

A customizable list of the attributes that can be applied to individual members and panels.

See: Create and manage user-defined attributes

Reinforcement
Rib type - vertical, Class - vertical Specifies the vertical reinforcement properties
Rib type - link/confinement, Class - link/confinement Specifies the link/confinement properties.
Stack 1, 2, 3 etc.

In a multi-stack column properties can be entered for a specific stack, over-riding those defined at the All stacks level.

Splice,

Splice offset

Used to indicate a splice at the bottom of a stack, and the offset above the floor level.

See: Splice and splice offset

Level 1, 2, 3 etc.
Load reductions

KLL

(Head Code ACI/AISC)

Specify the KLL factor in accordance with Table 4-2 in ASCE 7-05/ASCE 7-10.

See: Overview of live or imposed load reductions

Count the floor as being supported

(Head Code Eurocode, BS or IS)

If checked, the floor will be treated as supported when calculating the live/imposed load reductions.

See: Overview of live or imposed load reductions

Eccentricity (steel only)

Apply face A eccentricity, etc.

See: Steel column connection eccentricity moments

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