Column Design Settings

Column Design Settings

Column Design Settings

The “Settings and Parameters” form can be displayed by clicking the “Settings and Parameters"  icon in the “Column Reinforcement Design” form.


Column design and drafting can be easily controlled with the help of the parameters in this form.

Min Steel Percentages

The parameters on this sub-page control the reinforcement selection. 


Min. Column Steel Ratio

Minimum steel percentage to be used in a column is given on this page. If the steel area required in a column section is less than the minimum steel area required then the minimum steel percentage given in this field will be used automatically.

Max. Column Steel Ratio

Maximum steel percentage that can be used in a column section is given in this field. If the required steel area in a column exceeds this value, than the section will be considered as insufficient and a warning message will be displayed.

Min. Wall Longitudinal Steel Ratio

Minimum steel percentage to be used in walls is given using this field. If the steel area required in a wall section is less than the minimum steel area required then the minimum steel percentage given in this field will be used automatically.

Max. Wall Longitudinal Steel Ratio

Maximum steel percentage to be used in walls is given using this field. Steel area exceeding the value provided here is not permitted.

Min. Wall Horizontal Steel Ratio

Minimum steel percentage for horizontal steel area to be used in a wall is given on this page. If the steel area required in the horizontal direction in a wall section is less than the minimum steel area required then the minimum steel percentage given in this field will be used automatically.

Use Plain Wall Design

When this option is checked the program will use plain wall design (i.e. design based on no reinforcement) where it is applicable, resulting in a reduced minimum area of steel.

Moment Capacity Tolerance

In some cases, you may want to use less steel than required in the column sections. By introducing a percent “positive” tolerance in this field, you may accept a higher moment capacity for the concrete section and thus make the program put less steel than required. Likewise, negative values will yield greater steel areas than required.

Parameters (BS8110 & CP65)

On this sub-page you can specify the design clause to be applied where alternatives are offered in the design code. 

Bi-axial Bending Method

  • The method that will be used for bi-axial bending of columns can be selected using the available option in this field. Ultimate Strength Bi-axial Bending method will be used if "Bi-axial" is selected.
  • Alternatively, moment combination method described in "BS8110 (Cl 3.8.4.5)" or "CP65 (Cl 3.8.4.5)" may be used. When this option is checked, an effective moment will be calculated based on the x and y direction design moments and uni-axial bending is applied in this direction.

Design Ultimate Axial Load

  • Maximum axial load that can be carried by the columns and walls in the structure can be determined using one of these options. 

Steel Bars Selection Method

Selection Method

On this sub-page you can specify the steel bar layout method adopted in design mode. 


  1. Fixed Bar Layout Method
Program does not modify the steel bar layout in this method. Only the bar sizes are determined based on the given layout during design process.

The initial bar layout is determined based on the maximum bar spacing allowed by the current concrete codes.

  1. Bar Spacing Maximization Method

In this method, program modifies the layout so that the steel bar sizes are maximised to achieve the biggest possible spacing (within the spacing range specified in settings) between the bars.

  1. Bar Size Minimization Method

In this method, program modifies the layout so that the steel bar spacing is minimised (within the spacing range specified in settings) to achieve the smallest possible bar sizes to be selected.


Column Confinement

On this sub-page you can indicate your preference for the link pattern(s) you want to be considered in order to meet column confinement requirements when in design mode.
The program will select from the considered patterns the one which best matches the number of bars and bar spacing in each direction. It will also add tie bars where they are required.

For square columns and rectangular columns of reasonably equal side (b/h < 1.8) you can apply different preferences to those for rectangular columns of un-equal side b/h > 1.8).

Up to four link patterns can be considered from the following list:

  • Single Link  (this pattern is always considered).
  • Double Link
  • Triple Link.
  • Cross Link

Basic Column Confinement Requirements

In the BS8110 cl 3.12.7.2 requirements there are two cases to consider (EC2, CP65 and HK-2004 are similar):
  1. Where bar spacing exceeds 150mm: Every bar should be restrained by the corner of a link or by a tie.
  2. Where bar spacing is less than 150mm: Corner Bars should be restrained by the corner of a link or by a tie. Every alternate bar should be restrained by the corner of a link or by a tie
  • The maximum vertical spacing of these links and ties is 12 times the smallest main (vert) bar diameter.
  • Note that the limits on the vertical spacing of containment steel are different in EC2 which allows for closer spacing near supports and increased spacing in the span.

Wall Confinement

In design mode the program will attempt to satisfy the code requirements for wall confinement by adopting the link and tie pattern you choose on this sub-page.

Any one of four patterns can be specified in order to satisfy the containment requirements.

You can specify a particular pattern for short walls (Length/Thickness < 6) and a different one for long walls (Length/Thickness > 6).

The following patterns are available:

  • Wall
  • Wall with End Zones
  • Single Layer Wall
  • Single Layer Wall with End Zones


Max. Width for Single Layer Walls

A single layer of reinforcement may be appropriate in thinner walls.

You can use this setting to specify the maximum thickness of wall in which a single layer of reinforcement is to be used. The single layer may be either mesh or loose bars and it may be used in conjunction with end zone reinforcement.

Basic Wall Confinement Requirements

In the BS8110 cl 3.12.7.4&5 requirements there are two cases to consider (EC2, CP65 and HK-2004 are similar):
  1. When the main steel requirement < 2%, then only horizontal reinforcement is required.
  2. When the main steel requirement > 2%, then additional containment ties must be introduced.
  • Where bar spacing exceeds 150mm: Every bar should be restrained by the corner of a link or by a tie.
  • Where bar spacing is less than 150mm: Corner Bars should be restrained by the corner of a link or by a tie. Every alternate bar should be restrained by the corner of a link or by a tie

The maximum vertical spacing of these ties is twice the wall dimension or 16 times the smallest main (vert) bar diameter.

Note that the limits on the vertical spacing of containment steel are different in EC2, being 0.6 times the wall dimension or 12 times the smallest main (vert) bar diameter.

The EC2 requirement in this instance seem onerous so that it may be preferable to limit main steel to 2% and adjust wall sizing if this is not adequate.

Longitudinal Steel

The parameters on this sub-page control the steel bar selection in design mode.

Column Min/Max Bar Sizes

The minimum and maximum longitudinal bar diameters that can be used in columns can be entered using these fields. When a bar greater than the maximum size specified here is used for any reason, then a warning message will be issued.

Wall Min/Max Bar Sizes

The minimum and maximum longitudinal bar diameters that can be used in walls can be entered using these fields. When a bar greater than the maximum size specified here is used for any reason, then a warning message will be issued.

Min. Bar Spacing

Minimum bar spacing that can be used in columns can be entered in this field.

The value specified here should be greater and equal to the requirements stated in the codes. In cases that smaller values than "Min. Bar Spacing" is to be used, the program will automatically assume the code minimums.

Max. Bar Spacing

Maximum bar spacing that can be used in columns can be entered in this field.

Steel Bar Spacing Step

“Bar Spacing Step” is used in bar selection methods other than "Fixed Bar Layout Method" to increase and decrease bar spacing by the amount specified here.
Smaller values used as "Bar Spacing Step" may increase the design time considerably. A typical value of "5 mm" can be used in most cases.

Use Similar Bars as Web Bars for Walls Without EndZones

When this option is checked corner bars will have the same diameter as the web bars in the design of the walls without endzones.

Concrete Cover

Concrete cover is measured from the outside edge of the column to outside edge of the links. If the value in this field is zero, the concrete cover will be calculated according to the requirements in the current concrete codes.

When this value is modified, a message will appear that will propose modifying all the columns in the building. If a filtering option is active in the column table, the modification will affect only the filtered columns.
The parameters on this sub-page control the link bar selection in design mode. Layout methods can be set using the options provided in these pages. Furthermore, by using the options in “Links” page you can control the shear design, and selection of links.

Minimum bar size to be used for column and wall links can be defined in these fields. Greater bars sizes will be selected when necessary by the program.
Minimum and maximum link spacing to be used in columns can be defined in this field. A greater link bar size will be selected when the minimum link spacing is encountered during shear design.
Link spacing values will be rounded up according to the “Link Spacing Step”. For example, if the Link Spacing Step is “25 mm”, spacing values calculated will be rounded up as 150, 175, 200-mm etc. Also, while selecting the proper link spacing, the program increments the spacing by the “Link Spacing Step” defined in this field.
If you check the “Create Support Regions for Links” option, link spacing for the supports and the span are calculated separately.  In order to use same spacing for both span and supports, you must uncheck this checkbox.
If this field is checked, links in support regions will continue to be used inside the beam-column intersection (joint) in order to provide better confinement and shear resistance.

Mesh Steel

The parameters on this sub-page control the mesh bar selection in design mode.

Use Loose Bars When Mesh Size Not Sufficient

In the cases where design cannot be done with the largest mesh in the mesh library for a particular wall, program will automatically switch to loose bar pattern if this field is checked.  User, in further design phases, can specify program to revert and “try using mesh steel” during batch mode design if loose bar pattern is automatically used.

Min. Wall Length for Mesh Steel

If wall length is shorter than the value entered to this field then mesh steel would not be used in the design.

Mesh Width

Standard mesh panel width values can be entered in this field. Mesh panels will be drawn and cut where necessary according to the value entered here. If special production meshes or single mesh panels are used through the wall length, A value of “0” must be entered. Cut meshes are overlapped with a distance specified in “Mesh Lap/Anchorage Length” field. 

Mesh Lap/ Anchorage Length

If a standard mesh width is specified in Mesh Width” field, then mesh panels will be used at this width. Adjacent meshes will be lapped using the value entered in “Mesh Lap/Anchorage Length” field.  Mesh panels will also be extended into wall end zones using this value.

Extend Mesh Steel along the Length of EndZone

If checked, mesh panels will be extended and drawn through the length of the wall end zone. Mesh bars inside the end zone are ignored during the design calculations.

Detail Drawings

General

General parameters controlling the column drawings can be set using the options provided on this subpage.


Column links can be drawn either with all the segment lengths printed or with only the total length. If you check the “Print Column Links Segment Lengths” option, then all the segment lengths of the links will be displayed on the drawing.

Column Bars Bob Length

Bob length for longitudinal reinforcement in the column application plan is controlled by using this field.

Column Bars Kicker Depth

In each storey level, column longitudinal bars start in a small distance above the slab level. This distance can be defined as the “Column Bars Kicker Depth” field.

Mesh Steel Kicker Depth

In order to account for the kicker concrete in tunnel form constructions, “Mesh Steel Kicker Depth” value can be entered in this field. Mesh panels will be offset from the bottom of the wall by an amount of kicker depth and drawn accordingly.

All link details for all columns/walls can be expanded automatically in batch mode next to the drawing sheet in column application plan. This field determines the width to be allocated for link details drawing block.

You can use the available options in this field for the type of the single links that will be plotted in columns and walls.

Column Details

Further parameters controlling the column drawings can be set using the options provided on this subpage.


Column Detail Drawings Scale

You can enter the scale factor that will be used in the column detail drawings. This Drawing Scale will only affect the size of the text entities and the special marks.

Display Steel Bars to the Right of the Detail

The steel bars are redrawn to the right of the detail if this field is checked.

The steel bar detail lengths will be added to the detail if this field is checked.

The steel bar total lengths will be added to the detail if this field is checked.

Display Section Below the Detail

The section is added below the detail if this field is checked.

The depth which the links are shown penetrating into the foundation can be set using this field.

Column Schedule

Parameters controlling the column schedule can be set using the options provided on this subpage.


Column Schedule Drawing Scale

You can enter the scale factor that will be used in the column schedules. This Drawing Scale will only affect the size of the text entities and the special marks.

Draw Column Insertion Axis

Column insertion axes will be drawn when this field is checked.

Dimension Column Insertion Axes

Column insertion axis dimensions will be drawn if this field is checked.

Dimension Column Section

Column section dimensions will be drawn if this field is checked.

Center Column Labels and Texts in Cell

The justification of the text objects in a schedule cell can be set using this field. Column labels and steel bar texts will be centered if this field is checked. Otherwise, all texts will be left justified.

Draw Separator Lines between Label Texts

Horizontal separator lines will be drawn between the text objects if this field is checked.
The insertion axes of the columns will be printed below the schedule if this field is checked.

Draw Column Vertical Separator Lines

Vertical separator lines will be drawn between the columns if this option is checked.

Do Not Include the Unselected Storeys in the Table

You can select the storey to be included in the schedule using the "Storeys" list in the "Column Schedule" dialog. If this option is checked, the unselected storeys between the first and storey entered in the "Topmost Storey in the Sheet" field will not be drawn in the schedule.
If this option is checked, the label of the bottom column will be printed below the schedule. Column labels will be included in every cell if this option is not checked.
If this option is checked, the storey labels will be printed above the row. The storey labels will be printed inside the related row (in the leftmost cell) if this option is not checked.

Similar Storey Note

You can enter the string that will be displayed for annotating the columns that are similar as the ones below. "AS BELOW" is provided as default in this field.

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