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Structural Engineering Software


Reinforced Concrete Column Design

Interactive Column Design

The SPACE GASS reinforced concrete column design module lets you design or check any of the concrete columns in your structural model.

  • Fully integrated into SPACE GASS.
  • Design actions obtained directly from the analysis results.
  • Multiple load cases considered simultaneously.
  • Design and checking modes available.
  • Fully rendered 3D images and 2D cross sections of each column designed or checked.
  • Flexural and shear reinforcement designed or checked.
  • Circular, rectangular, tee, trapezoidal, cruciform and flat oval cross sections are supported.
  • Multiple voids of any shape or size.
  • Axial, moment (uniaxial and biaxial) and shear considerations taken into account.
  • Calculation and display of interaction curves.
  • Priority settings available for "minimum steel" or "minimum bars".
  • Moment magnification available.
  • Exporting of drawings to DXF or DWG files.
  • Reinforcing bar libraries.
  • Fully compliant with AS3600 and IS456.

Operating the module simply involves you selecting the members that form a column and then selecting the concrete column design module. The column is immediately designed and presented to you as a fully rendered 3D image and cross section in the column editor. From there you can examine it in more detail by zooming, panning or rotating, or you can change any of the design parameters or reinforcement to meet your exact requirements.

Each time you make a change, the column is automatically re-checked or designed and the 3D image and cross section is updated so that you can see exactly what is happening as you go.

Column design video

Interaction Diagrams

Interaction diagrams representing the axial versus moment capacity of a column show you immediately which load cases have passed or failed and by how much.

You can hover the mouse cursor over any part of the interaction diagram to show the underlying values at the cursor's location.

A shaded confinement region can be displayed that shows whether extra fitments are required to provide confinement to the main bars.


The cross section panel shows the cross section and reinforcement, while the "2D View" tab in the column view panel shows the longitudinal section for the entire column.

Fully detailed cross section and longitudinal section drawings can be exported to DXF or DWG files for use in your CAD system.


Multiple voids of any shape or size can be included in the cross section and taken into consideration in the column calculations. You simply add them as negative shapes in the shape builder when you are creating your cross section for the analysis model.

Data Panel

The data panel on the left of the column editor lets you control the load cases to be considered, biaxial versus uniaxial checks, shear checks, minimum design actions, moment magnifiers, effective lengths, reinforcement percentages, bar sizes and design priorities.

Design mode

When performing a design, SPACE GASS evaluates many solutions (sometimes hundreds), discards the impractical ones and then sorts the rest according to the "Design Priority" setting that you have selected. For example, if you have selected "Minimum bars" then it will put the solution that has the minimum number of bars first and present that as the optimal solution. "Minimum steel" gives the most efficient design in terms of total area of steel, however it usually results in quite small bar sizes and so is often impractical. "Minimum bars" gives the best result in most circumstances.

If you have the "Auto" option at the bottom of the form ticked and the column is not locked (ie. the padlock button at the bottom is green) then whenever you make a change to any of the design parameters, the design is repeated and the reinforcement updated. Of course you can untick the "Auto" option if you don't want this to happen automatically.

Check mode

If you manually change any of the bar counts or sizes in this panel then the column will become locked (ie. the padlock button at the bottom will become red) and any further changes you make to the design parameters will simply cause the reinforcement to be checked rather than be changed. Alternatively, if you wish to lock the bar counts, but still allow the bar sizes to change then you could tick the "Lock bar count" option. In this case a re-design could cause the bar sizes to change but the number of bars would remain as they were.

You can even open the bar table and change individual bars if required.

Management Form

The concrete management form lets you manage all your reinforced concrete beams and columns in one convenient location. You can re-design or re-check them in batch mode, view the results, generate reports or open any member in the beam or column editor.

Status Bar

The status bar at the bottom of the editor or management form lets you see at a glance whether the column has passed, failed or passed with a warning. It includes the critical load case, the utilization ratio and a brief explanation of the failure mode or warning message. A green line indicates it has passed, red indicates failure and yellow is for a pass with a warning message.


Reports contain all of the key information for the column design, including the critical interaction diagram and a complete reinforcement specification. More detailed reports also include a bar table and a table of the interaction points.


You can click the "Preferences" button to open the concrete column preferences form and then change the defaults for various concrete parameters such as the default bar library, spacings, cover, size ranges, colors and other options.