STAAD Foundation Advanced Help

Using a Variable Bearing Capacity Table for Design

To use a variable soil bearing capacity table for design of footings, use the following procedure.

In order to utilize a variable bearing capacity table, the Use Variable Bearing Capacity option must first be set on the Global Settings dialog Rigid Foundation Settings tab within the Bearing Capacity Settings group.
Note: This is a global setting and, thus, is not saved with the file. The option setting (set or clear) is retained regardless of the file open.
Note: Variable bearing capacity tables may only be used with isolated footings designed per US codes.
  1. Select the Soil Properties > Variable Soil Bearing Table entry in the Main Navigator pane. The Variable Soil Bearing Capacity form opens in the Data Input Pane.
  2. (Optional) Select an existing table to edit from the Select Table drop-down list.
    Tip: You can remove an all the data in an existing table by clicking Delete Table.
    The table values are displayed and may be edited as described in Step 5.
  3. Type the No. of Embedment Depths (i.e., table rows) and the No. of Dimensions (i.e., table columns) in the respective fields.
  4. Type a unique Table Name and then click Create Table. The empty table is created.
  5. Type the footing dimensions, B, in row 2 of the table and type the embedment depths in the Df column.
  6. Type the corresponding bearing capacities for each embedment depth and footing dimension in the appropriate table cell.
  7. Click Save Table. A message dialog confirms the table has been saved. Click OK to continue.
  8. Select the Isolated Footing Job > Design Parameters > Cover & Soil entry in the Main Navigator pane. The Cover and Soil form opens in the Data Input Pane.
  9. In the Soil bearing capacity field, select the name of the variable bearing capacity table from the drop-down list.
    Note: This field is only a drop-down list if the Use Variable Bearing Capacity option is set on the Global Settings dialog Rigid Foundation Settings tab.
The variable bearing capacity values will be used during design of the footing. Linear interpolation & extrapolation is used for embedment depths and footing dimensions that are not explicitly listed in the table when those are specified or determined by the program.