Example Problems

Example Problem 1: A square footing $2m \times 2m$ is founded at a depth of $1.5m$ in a uniform sand deposit with $\gamma = 18 \, kN/m^3$, effective cohesion $c'=0$, and friction angle $\phi = 35^\circ$ ($N_c=46, N_q=33, N_\gamma=48$). Calculate the ultimate bearing capacity. The water table is deep.

Example Problem 2: Re-calculate Problem 1 if the site experienced heavy flooding and the water table rose precisely to the ground surface ($D_w = 0$). Assume the saturated unit weight $\gamma_{sat} = 20 \, kN/m^3$.

Example Problem 3: A rectangular foundation $1.5 \, m \times 2.0 \, m$ is placed at a depth of $1.2 \, m$ in a stiff clay. The clay is saturated and tested under undrained conditions, yielding an undrained shear strength of $120 \, kPa$ and zero friction angle. The unit weight of the clay is $19 \, kN/m^3$. Determine the net ultimate bearing capacity using Skempton's modified bearing capacity factor.