Question

The following two statements are made with reference to the calculation of net bearing capacity of a footing in pure clay soil $(\varphi =0)$ using Terzaghi's bearing capacity theory. Identify if they are TRUE or FALSE
I. Increase in footing width will result in increase in bearing capacity.
II. Increase in depth of foundation will result in higher bearing capacity.

• A. Both statement are TRUE
• B. Both statement are FALSE
• C. I is TRUE but II is FALSE
• D. I is FALSE but II is TRUE

Answer 1

The correct option is B Both statement are FALSE

As per Terzaghi, net ultimate bearing capacity
$q_{nu}=C{N}_c+q(N_q-1)+\frac{1}{2}B\gamma N_{\gamma }\dots \dots \left(i\right)$

$For,\varphi =0$

$N_c=5.7;N_q=1;N_{\gamma }=0$

From (i)

$q_{nu}=5.7\text{C}$

Thus, net ultimate bearing capacity for pure clay soil $(\varphi =0)$ is independent of width and depth of footing.
Hence, the correct option is (b).