ABSTRACT
The shape of the curve depends generally on the size and shape of the footing, the composition of the supporting soil, and the character, rate, and frequency of loading. Normally a curve will indicate the ultimate load Q
u that the foundation can support. If the foundation soil is a
dense sand or a very stiff clay, the curve passes fairly abruptly to a peak value and then drops down as shown by curve C1 in Fig. 10.2(b). The peak load Qu is quite pronounced in this case. On the other hand, if the soil is loose sand or soft clay, the settlement curve continues to descend on a slope as shown by curve C2 which shows that the compression of soil is continuously taking place without giving a definite value for Q
u • On such a curve, Q
u may be taken at a point beyond which
there is a constant rate of penetration.
