This Spreadsheet is intended to help practising engineers to quickly optimise pad foundations.
Pad foundations are generally shallow foundations, but can be deep depending on the ground conditions. They are a form of spread foundation formed by rectangular, square, or sometimes circular concrete ‘pads’ that support localised single-point loads such as structural columns, groups of columns or framed structures.
This load is then spread by the pad to the bearing layer of soil or rock below. Pad foundations can also be used to support ground beams.
They are generally of a uniform thickness, but sometimes the upper face may be sloped or stepped. Their plan shape will depend on the nature of the applied load and the allowable bearing capacity of the layers below. Their thickness must be sufficient to distribute the load across the plan shape.
They are generally reinforced on all but the smallest structures, with the reinforcement allowing higher loads to be imposed and the construction of shallower pads which require less excavation and use less concrete.
The arrangement of pad foundations will vary depending on the nature of the structure they are supporting, the loads imposed, the allowable bearing capacity of the layers below and the space available on site.
This spreadsheet designs simple pad foundations from input of material properties, dimensions and characteristic loads and moments.
Pad Foundations Spreadsheet 1 – Download
Pad Foundations Spreadsheet 2 – Download