DHARMBEARING CAPACITY 545Note 1. Values listed in the table are from shear consideration only.
Note 2. Values are very much rough for the following reasons:
(a) Effect of characteristics of foundations (that is, effect of depth, width, shape, roughness,
etc...) has not been considered.
(b) Effect of range of soil properties (that is, angle of internal friction, cohesion, water table,
density, etc.) has not been considered.
(c) Effect of eccentricity and inclination of loads has not been considered.
Note 3. For non-cohesive soils, the values listed in the table shall be reduced by 50 per cent, if
the water table is above or near the base of foooting.
Note 4. Compactness or looseness of non-cohesive soils may be determined by driving the cone of
65 mm dia and 60° apex angle by a hammer of 65 kg falling from 75 cm. If corrected number of blows (N)
for 30 cm penetration is less than 10, the soil is called loose, if N lies between 10 and 30, it is medium,
if more than 30, the soil is called dense.
Limitations of Bearing Capacity values for building codes
The following are the limitations of the bearing capacity values specified in building
codes:
(i) By specifying a value or a range for bearing capacity, the concept is unduly oversim-
plified.
(ii) The codes tacitly assume that the allowable bearing capacity is dependent only on
the soil type.
- Medium clay, readily indented
with a thumb nail
245 (25)- Moist clay and sand-clay mix-
ture which can be indented with
strong thumb pressure
150 (15)- Soft-clay indented with moder-
ate thumb pressure
100 (10)- Very soft clay which can be pen-
etrated easily with the thumb
50 (5)- Black cotten soil or other
shrinkable or expansive clay in
dry condition (50% saturation)
— See note 3. To be deter-
mined after investiga-
tion
IV. PEAT- Peat — See note 3 and note 4
To be determined after
investigation
V. MADE-UP GROUND - Fills or made-up ground — See note 2 and note 4
To be determined after
investigation.