Design of Rectangular Column Footing
Design of Rectangular Column Footing are a special case of rectangular columns, formed with the foundation footing.
Such structural solution significantly facilitates installation of an element at the construction site. We may manufacture column footings of rectangular section of large heights up to a few floors. The column footings are equipped with the installation accessories for the floor beams, roof beams, and walls.
Depth of Footing
The depth to which foundations shall be carried is to satisfy the following:
- Ensuring adequate bearing capacity.
- In the case of clay soils, footings are to penetrate below the zone where shrinkage
- and swelling due to seasonal weather changes are likely to cause appreciable
- The footing should be located sufficiently below maximum scouring depth.
- The footing should be located away from top soils containing organic materials.The footing should be located away from unconsolidated materials such as garbage.
All footings shall extend to a depth of at least 0.50 meter below natural ground level. On
rock or such other weather-resisting natural ground, removal of the top soil may be all that
is required. In such cases, the surface shall be cleaned, so as to provide a suitable bearing.
Usually footings are located at depths of 1.5 to 2.0 meters below natural ground level.
It represents the simplest, most economical type and most widely used footing. Whenever possible, square footings are provided so as to reduce the bending moments and shearing forces at their critical sections. Isolated footings are used in case of light column loads, when columns are not closely spaced, and in case of good homogeneous soil. Under the effect of upward soil pressure, the footing bends in a dish shaped form. An isolated footing must, therefore, be provided by two sets of reinforcement bars placed on top of the other near the bottom of the footing. In case of property line restrictions, footings may be designed for eccentric loading or combined footing is used as an alternative to isolated footing.