Demo provided below regarding creating of design for rectangular pile cap with the help of spreadsheet given below.
The regular features of the spreadsheet are clearly discussed here which is effective used for making the design (according to BS 8110-1:1997) of rectangular pile caps with 4 or more piles.
1.0 ASSUMPTIONS AND CONSTRAINTS OF THE SPREADSHEET:
1) The pile cap is assumed to be inflexible.
2) This spreadsheet is determined for rectangular pile caps as the same is not applicable for octagonal or irregular shaped pile caps.
3) This spreadsheet can be only used for pile caps containing single pedestal/column as the Pile caps for multi-pedestals/columns are out of the extent.
4) Minimum numbers of piles should be 4 and Maximum number should be 28 (as Individual spreadsheets are formed with pile caps having 2 piles & 3 piles).
5) For coordinate axes, centroid of pedestal is taken as the source.
6) Eccentricity of horizontal loads relating to C.G. of pile cap is not taken into consideration.
7) Highest load cases are constrained to 100.
8) The diagrams demonstrating the plan of pile cap is characteristic only which is meant to provide the direction of co-ordinate axes. On the basis of the input the number of piles/size of pile cap provided will not be modified.
9) In order to verify the ability either two conditions are taken into consideration
a) Design water table either at ground level b) Underneath the founding depth of pile cap.
Intermediate levels among these two are not considered.
2.0 SPECIFICATION OF THE SPREADSHEET:
1) For designing the pile cap, STAAD analysis output is directly entered as the input.
2) Choices to create the design of pile cap either for the whole capacity of pile or for the actual pile loads. All the pile loads are considered as compression capacity to design with whole capacity of piles for working out the bottom reinforcement. All the pile loads are considered as tension capacity for working out the top reinforcement.
3) All inputs are explained in rose color and the output in yellow color for quick reference.
4) To defend the spreadsheet from any unpremeditated change/modification all cells excepting the input cells are locked.
5) As water table should be calculated in the tension capacity of pile water table is assessed In the spreadsheet and the loss in self weight of pile.
To download the spreadsheet, click on the following link