12-03-2014, 09:56 AM
. Combined footings are footings that support more than one column or wall.
. Combined footings can be used in case :
1. an exterior column that is immediately adjacent to a property line where it is
impossible to use an individual column footing.
2. two columns that are closely spaced, causing their individual footings to be closely
spaced.
. The choice of which shape (rectangular or trapezoidal) to be used is depends on the difference ¡n column loads and on physical/ dimensional limitations.
. The physical dimensions (except thickness) of the combined footing are generally established by the soil bearing capacity of the soil.
. In addition, the centroid of the footing area should coincide with the line of action of
the resultant of the two column loads.
. These dimensions are determined using service loads in combination with an
allowable soil bearing capacity.
. Combined footings can be used in case :
1. an exterior column that is immediately adjacent to a property line where it is
impossible to use an individual column footing.
2. two columns that are closely spaced, causing their individual footings to be closely
spaced.
. The choice of which shape (rectangular or trapezoidal) to be used is depends on the difference ¡n column loads and on physical/ dimensional limitations.
. The physical dimensions (except thickness) of the combined footing are generally established by the soil bearing capacity of the soil.
. In addition, the centroid of the footing area should coincide with the line of action of
the resultant of the two column loads.
. These dimensions are determined using service loads in combination with an
allowable soil bearing capacity.