Stress Distribution

The values of Influence factors given above was given by Gilboy (1953) , but the influence factor for

shear stress can be found out by multiplying the influence factors by the ratio of r/z. For r=0, Influence factor = .4775 PRESSURE DISTRIBUTION DIAGRAM: Following pressure distribution diagram can be drawn by using the Boussinesq’s stress distribution theory: 

Stress isobar or isobar diagram

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Vertical pressure distribution on a horizontal plane

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Vertical pressure distribution on a vertical plane

STRESS ISOBAR OR ISOBAR DIAGRAM: D IAGRAM:

An isobar is a line that connects all points of equal stress increment below the ground surface. In other words, an isobar is a stress increment contour. Each isobar represents a fraction of the stress applied at the surface and delineates the zone of influence of the footing such that the area contained within two adjacent isobars experiences stresses greater than the lower isobar and less than the upper isobar. Since these isobars form closed figures that resemble the form of a bulb,