Column and Shearwall Design Settings

Column and Shearwall Design Settings

General

Column and shearwall design setting is important to preset before starting to design any columns/walls. By presetting these design parameters can save a significant amount of time for user compare to user who set after designing columns/walls. This is to ensure the columns/walls are correctly designed based on the project criteria.

To access the Column and Shearwall Design Setting, user can:
  1. Go to "Building Setout" tab > "Settings Center" "Column & Shearwall", or
  2. click on “Setting and Parameters” in the “Columns Section Design Summary Table”.

Design

Min Steel Percentages

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

  1. Column
    1. Column Min. Steel Ratio : Minimum steel percentage to be used in column. 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.
    2. Column Limit Steel Ratio : Maximum steel percentage to be used in a column. 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.
  2. Wall : 
    1. Wall Min. Longitudinal Steel Ratio :  Minimum steel percentage to be used in wall. 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.
    2. Wall Limit Longitudinal Steel Ratio : Maximum steel percentage to be used in wall. If the required steel area in a wall exceeds this value, than the section will be considered as insufficient and a warning message will be displayed.
    3. Min. Wall Horizontal Steel Ratio :   Minimum steel percentage for horizontal steel area to be used in a wall.  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.
    4. Use Plain Wall Design :  Apply plain concrete wall design where it is applicable, resulting in a reduced minimum area of steel.
  3. Moment Capacity ToleranceIntroduce tolerance for required steel in the column sections. Apply positive % tolerance means accept a higher moment capacity for the concrete section and thus  reduce steel area than required. Likewise, negative values will reduce moment capacity which increase steel area required.

Parameters

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

  1. Max. Effective Length Factors (BS8110 & CP65) : To set the maximum effective length factors. ProtaStructure calculates effective length using the formulae given in clause 2.5 in BS 8110‐2:1985. Therefore, the limit will be 4. This setting will not affects project using Eurocode template.
  2. Joints Shear Check (Seismic Related only) This check will only be done if specific region code with high seismic zone & high ductility is required (example, Philippines Code)
  3. Design Ultimate Axial Load (BS8110 & CP65) Maximum axial load that can be carried by the columns and walls in the structure. Default option is using equation 39 (BS8110 part 1) which is slightly conservative.
  4. Bi-axial Bending Method (BS8110 & CP65) :  To select the method that will be used for bi-axial bending of columns.  "Bi-axial" means  Ultimate Strength Bi-axial Bending method "BS8110 (Cl 3.8.4.5)" or "CP65 (Cl 3.8.4.5)"  means  moment combination method. 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.

Rebar

Steel Bars Selection Method

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


  1. Selection Method
    1. Fixed Bar Layout Method : To remain the rebar layout as previously designed without modification. 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.
    2. Bar Layout Optimization Method :  Program modifies the layout so that the steel bar sizes are maximized to achieve the maximum spacing (within the range specified in setting) between the bars.

Column Containment

On this sub-page you can indicate the preference for the link pattern(s) 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.

  1. Column Link Patterns : To select link pattern(s) to be involved in column design (b/h <1.8 and b/h >1.8).
    1. Single Link  (this pattern is always considered).
    2. Double Links
    3. Triple Links
    4. Cross Link
    • B/H Ratio For Cross Links : - To allow cross links when column B/H is lesser than the defined width to height ratio. Where dimension B and H (<B) are the overall depth of the section.
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).
ProtaStructure will comply to the Basic Column Confinement Requirements according to each codes when auto arranging the links unless user overrides by manually defining.
For example : Eurocode 2 cl. 9.5.3 and BS8110 cl 3.12.7 requirements.

Wall Containment

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.

  1. Wal Containment Pattern :
    1. Wall
    2. Wall with End Zones
    3. Single Layer Wall
    4. Single Layer Wall with End Zones
  2. Max. Width for Single Layer Walls : 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.
You can specify a particular pattern for short walls (Length/Thickness < 6) and a different one for long walls (Length/Thickness > 6).
ProtaStructure will comply to the Basic Column Confinement Requirements according to each codes when auto arranging the links unless user overrides by manually defining.
For example : Eurocode 2 cl 9.6 and BS8110 cl 3.12.7.4&5 requirements.
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.

  1. Longitudinal Steel
    1. Column Bar Sizes (Min/Max) : Minimum and maximum longitudinal bar diameters that can be used in columns.
    2. Wall Bar Sizes (Min/Max) : Minimum and maximum longitudinal bar diameters that can be used in walls can be entered using these fields.
    3. Min. Column Steel Bar Spacing : Minimum bar spacing that can be used in columns. If user defined spacing is smaller than min. requirement from code, program will take the greater value as the final min. spacing. 
    4. Max. Column Steel Bar Spacing : Maximum bar spacing that can be used in columns.
    5. Max. all Web Steel Bar Spacing : Maximum longitudinal (vertical) bar spacing that can be used in walls. 
    6. Steel Bar Spacing Step : Spacing values will be incremented by the amount specified in this field during iterations. Smaller values used as  "Bar Spacing Step"  may increase the design time considerably.
    7. Use Similar Bars as Web Bars for Walls Without EndZones : Use similar bars size for corner bars as the web( vertical) bars  in the wall that has no endzones.
    8. Include Longitudinal Bar Spacing Checks to Design Status : Beam design status to include bar spacing check. If spacing check does not pass, design status will show fail.
  2. Concrete CoverConcrete 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 affected during auto design based on options provided.

  1. Links
    1. Min. Link Bar Size :  Minimum bar size to be used for column and wall links.
    2. Min. and Max. Link Spacing : Minimum and maximum link spacing to be used in columns.
    3. Link Spacing Step : Spacing values will be incremented by the amount specified in this field during iterations. 
  2. Link Properties
    1. Create Support Regions for Links : Link spacing for the supports and the span will be calculated separately. Uncheck to use same spacing for both span and supports.
    2. Provide Links Through Beam Depth : Links in support regions will continue to be provided inside the beam-column intersection/junction (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.

  1. Mesh Steel :
    1. Use Loose Bars When Mesh Size Not Sufficient :  Program will automatically switch to loose bar pattern if single mesh is not sufficient in wall design. User can specifies program to revert and  “try using mesh steel”  during batch mode design if this option is checked.
    2. Extend Mesh Steel along the Length of EndZone :  To extend mesh panels through the wall end zone. Mesh bars inside the end zone are ignored during the design calculations.
    3. Min. Wall Length for Mesh Steel : If wall length is shorter than the entered value, then mesh steel would not be used in the design.
    4. Mesh Width :  To specific the standard mesh panel width. Mesh panels will be drawn and cut where necessary according to the value entered. 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. 
    5. Mesh Lap/Anchorage Length : Adjacent meshes will be lapped using the entered value.  Mesh panels anchorage length will be extended into wall end zones based on this value.

Detail Drawings

General

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

  1. Kicker Depth
    1. Column Bars Kicker Depth (Dk) : To enter the length of column longitudinal bars protruded up from the slab level. In column elevation drawing, bottom of column (storey 1 and above) will leave the distance (space without rebars) for kicker depth. 
    2. Mesh Steel Kicker Depth (Dk) : To enter the length of mesh bars protruded up from the slab level. In wall elevation drawing, bottom of wall (storey 1 and above) will leave the distance (space without rebars) for kicker depth. 
    3. Foundation Penetration Depth of Links (Dp) : To enter depth of links that penetrated downwards into the foundation (ie. storey 0).
    4. Starter Bars Length Factor (FI) : To set starter bars length based on the multiplier of rebar diameter. This applies to the length of starter bars protruded from top of all columns. 

  2. Rebar Bob Control : Select the option to detail the bend of bars of top column rebar at the highest storey.
    1. Bottom Bob Factor : To set bend of bars length at bottom of column based on the multiplier of rebar diameter. This applies only to column connects to foundation. 
    2. Top Bob Factor : To set bend of bars length at top of column based on the multiplier of rebar diameter. This applies only to column that has no continuity of column above it. 
  3. Lateral Web Bar Placement : To set horizontal rebar arrangement/placement based with the given selections:
    1. Outside of Longitudinal Bars
    2. Inside of Longitudinal Bars
    3. Crank into Head Zone
  4. Single Link Type (Columns and Walls) : Select the type of the single links that will be plotted in columns and walls.
  5. Longitudinal Bar Lap Position For Columns : Select the lapping position for column to be either near at the bottom of the column (Left option) or middle of the column (Right option).
  6. Longitudinal Bar Lap Position For Walls :  Select the lapping position for wall to be either near at the bottom of the column (Left option) or middle of the column (Right option).
  7. Lateral Bar :
    1. Draw BOB for Shearwall Lateral Bars : Check to allow lateral bar in wall to form bending of bar.

Elevations

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

  1. Shearwall Opening : To select standard rebar layout pattern of the wall opening.
    1. Rebar Spacing : To set the spacing of wall rebar arranged in local direction y.
    2. Use Corner Bar : To plot diagonal corner bars at the corners of the wall.
    3. Diameter : To set rebar diameter of the corner bar.
Please refer to this article :  Working with Walls > Editing an Existing Wall  to understand the limitation of wall opening in analysis and design. 
  1. Display Section : To display column section beneath the column elevation detail drawing.
    1. Draw Column Insertion Axes : To include column insertion axes in the column section.
      1. Dimension Column Insertion Axes : - To include dimension measuring from the insertion axes in the column section.
      2. Write Axes Labels On Section : - To include axes label in the column section title/label.
    2. Dimension Column Section : To include dimension of the column section.
  1. Shearwall Longitudinal Bar Extension : To detail the longitudinal bar when there is a column above the wall.
    1. Extend into Upper Column : Extend the longitudinal bar into the column above
    2. Truncate : Stop the longitudinal bar from extending into the column above.

  2. Other Setting :
    1. Display Steel Bars to the Right of the Detail : To display the steel bars by redrawing at the right hand side of the column elevation.
    2. Print Steel Bar Detail Lengths : To include detail dimension of the column steel bar (length of each bend).
    3. Print Steel Bar Total Lengths : To include the total length of column steel bars.
    4. Draw Beam Sections Connected From Other Directions : To include incoming beam section from front/back in the column elevation drawing.

Column Schedule

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

  1. Section Draw Options : This shows the column section in Column Schedule (not to confuse with Column Elevation).
    1. Draw Column Insertion Axes : To include column insertion axes in the column section.
      1. Dimension Column Insertion Axes : - To include dimension measuring from the insertion axes in the column section.
      2. Write Axes Labels On Section : - To include axes label in the column section title/label.
    2. Dimension Column Section : To include dimension of the column section.
  1. Table Look :
    1. Draw Column Vertical Separator Lines : To draw vertical lines as a separator between the column section.
    2. Draw Separator Lines between Label Texts : Draw To draw horizontal line as a separator for labels/texts.
    3. Print Storey Labels above the Column :   To print the storey labels at top of the column section inside the related row (in the leftmost cell).
  1. Table Content :
    1. Print Column Insertion Axis Labels : To show the insertion axes label of column at first row (with separator) of the column schedule table.
    2. Print Column Labels Below the Table : Show column labels in last row (with separator) of the column schedule table.. 
    3. Draw Outline of Change in Column Size : Show outline of bottom column section when column size change between lower floor column and current floor column. 
    4. Similar Storey Note : Note to be shown in top storey when top storey column is similar to bottom storey column. Default note is "AS BELOW".
    5. Show Link Details : To display link in detail by redrawing it at the right hand side of the column section.
    6. Link Count : When option "Show link Details" is active, this option is not visible. This option will show the link number below the column label:
      1. Hide : - Link number will be hidden.
      2. per floor : - Link number will be showed per floor.
      3. per section : - Link number will be showed per section.


    • Related Articles

    • Interactive Column Design

      In the “Column Reinforcement Design” column sections and reinforcement arrangement can be examined and changed interactively. Since columns and walls are the primary members of a structure, especially the critically loaded ones should be designed ...
    • Column Punching Shear Checks to BS 8110 and Eurocode 2

      The nature of the design code requirements tend to dictate that punching shear checks cannot be safely & fully automated in batch runs. For this reason, ProtaStructure’s punching shear check is an interactive design tool, you need to use it carefully ...
    • Beam Design Settings

      General Beam design setting must be preset correctly before starting any beam design. This is to ensure the beams are correctly designed based on the project criteria & user preferences. To access the Beam Design Setting, user can: Go to "Building ...
    • Column Punching Check

      Column Punching Check You can perform punching checks according to the selected concrete code using the “Column Punching Check” option located in the “Design” tab. The punching check calculations have been designed for flat slab structures and raft ...
    • Define Wall/Column Lateral Loads

      User-defined varying distributed lateral loads can be applied to the individual column and wall member. The span load applied maybe used to simulate : Soil Pressure on basement wall Hydrostatic load As an alternative to defining wind load (other than ...