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Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
settlement of the footings as compared to the isolated footing is
found. Similar observation is made for case d wherein the stress
isobars diverge or are in opposite direction hence negligible or
no overlap of stress contours is seen in the vicinity of footing
edges where the stress concentration will be high and at greater
depths of footings the stress contours overlap a bit. Henceforth,
it is observed that the interference phenomenon has no
significant effect on the bearing capacity; however it has certain
considerable effect on the settlement of the footings. It is also
observed that at the node point 1 m below the axis of symmetry,
the vertical settlement obtained for case c is higher than that
obtained for case d since in case c the footing loads on left and
right footings converge towards the axis of symmetry and vice
versa in case d.
Figure 9. Pressure settlement curves of case c and case d at S/B
equal to 0.5.
Figure 10. Stress contour for case c at S/B equal to 0.5.
Figure 11. Stress contour for case d at S/B equal to 0.5.
4
CONCLUSIONS
A limited study is presented on the effect of two closely spaced
rigid strip footings resting on the surface of homogeneous soil
subjected to inclined load. The effect of interference
phenomenon on ultimate bearing capacity and settlement at
working load condition are studied. The phenomenon has
certain considerable effect on the ultimate bearing capacity,
increasing its capacity when footings are vertically loaded. For
the cases where footings are subjected to inclined load the effect
of interference on the bearing capacity has no significant effect.
However for all the cases of inclined loading condition, the
interference effect on the settlement is quite significant. The
settlement of interfering footings in the range of working load
decreases with increase in the clear spacing between the
footings and attains a value as that of isolated footing at greater
clear spacing (S ≥ 5B).
5
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