Base Plate Design Spreadsheet

Base Plate Design for Steel Columns

Base plates are required for any steel column which connects to a concrete base. Usually this is where the lower columns of a steel frame connect to the concrete foundations which transmit the forces from the frame into the ground.

Steel base plates need to be large enough to spread the force from the column into the concrete. The base plate needs to spread the force sufficiently to ensure that the underlying concrete is not overstressed. The base plate needs to be thick enough to enable the force to spread through the base plate to the required effective area.

The column is welded to the base plate. In pinned columns there are no tensile forces expected in the base plate. However the weld is used to resist any shear forces and to ensure that the column is stable under any temporary conditions during installation or operation.

Base Plate Design Procedure

The CivilWeb Base Plate Design XLS includes 5 different base plate design excel sheets in order to encompass all commonly used steel base plate connections. This includes the following base plate design xls;

• Pinned I Shape Columns
• Pinned RHS / SHS Columns
• Pinned CHS Columns
• I Shaped Moment Columns
• I Shaped Moment Columns Including Tension

Firstly the user must enter the details of the column. The spreadsheet allows the designer to choose from any standard I shaped beam or column section, RHS, SHS, or CHS section. The pre-set sections included in the I section spreadsheets include UB, UC, UBP, HE, IPE, HD, HLZ, HL and HP sections. The RHS and CHS spreadsheets include all standard sections used in the UK and Europe. Overall the spreadsheets include pre-set details for more than 2,500 different standard section sizes.

Next the user can enter the design loadings to be resisted by the base plate. The loadings can include axial compression, shear force and bending moments. The user must also enter the partial action factors to be used. Each base plate design excel sheet is pre-set with the partial action factors required under the Eurocode BS EN 1993-1-8, however these can each be altered if required to suit alternative design standards.

The final step for the user is to input the details of the welds, base plates and bolts. Each of the design sheets comes pre-loaded with standard bolt details. The spreadsheets include full geometric details for all standard bolt types between M1.6 and M64, 29 different types in total. The designer can also override the pre-set details if required to suit any non-standard bolt type.

The CivilWeb Base Plate Design Spreadsheet also creates a dynamic diagram showing the proposed base plate arrangement and key dimensions. This unique diagram prevents the user from accidentally entering the wrong dimensions into the spreadsheet. The user can use the diagram to check that the inputs have been entered correctly.

Now that the inputs have been entered, the spreadsheet can complete the calculations. All the calculations are completed automatically by the spreadsheet in accordance with the requirements of BS EN 1993-1-8. The spreadsheet calculates a utilisation factor for each critical calculation, showing the designer exactly how much of the base plates capacity is being used. This allows the designer to see at a glance whether the base plate is suitable or whether it is over or under sized.

The calculations undertaken automatically by the spreadsheet include;

• Effective Area of the Base Plate
• Resistance of the Underlying Concrete
• Weld Resistance
• Required Base Plate Size and Thickness

The CivilWeb Base Plate Design Spreadsheet presents all the calculations in either red or green for clarity. The spreadsheet also reproduces the results of the calculations in a handy summary at the top of the page. This allows the designer to see instantly the effects of any alterations made to the design without scrolling up and down the page.

The spreadsheet also draws unique analysis graphs which show the designer the effects of alterations to the critical design parameters including base plate size, thickness and fillet weld leg length. This allows the designer to see at a glance exactly the optimum size and thickness for the base plate without having to complete time consuming iterative calculations.

CivilWeb Base Plate Design Spreadsheet

The CivilWeb Base Plate Design Spreadsheet is an advanced spreadsheet for the design of base plates used for steel columns. The spreadsheet includes 5 separate design sheets for the design of pinned RHS, CHS and pinned or moment resisting base plates for I shaped columns. The spreadsheet completes the calculations instantly in accordance with the Eurocode BS EN 1993-1-8, and unique analysis features allow the designer to complete a fully optimised and fully compliant base plate design in minutes.

Buy the CivilWeb Base Plate Design Spreadsheet now for only £19.99.