Chapter 8, Problem 8.1P

To determine

Find the net ultimate bearing capacity value for the given properties of mat foundation.

Answer to Problem 8.1P

The value of net ultimate bearing capacity is $\underset{¯}{16.3{\text{kip/ft}}^2}$.

Explanation of Solution

Given information:

The depth of the foundation $\left(D_f\right)$ is $6.2\text{ft}$.

The length of the foundation $\left(L\right)$ is $30\text{ft}$.

The width of the foundation $\left(B\right)$ is $20\text{ft}$.

The coefficient of friction $\left(c_u\right)$is $\text{2,500}{\text{lb/ft}}^2$.

The angle of friction $\left(\varphi \right)$ is 0.

Calculation:

Find the net ultimate bearing capacity of mat foundation $\left(q_{\text{net}\left(u\right)}\right)$ as follows:

$\begin{array}{c}{q}_{\text{net}\left(u\right)}=5.14c_u\left(1+\frac{0.195B}{L}\right)\left(1+0.4\frac{D_f}{B}\right)\\ =5.14\times \text{2,500}{\text{lb/ft}}^2\left(1+\frac{0.195\times 20\text{ft}}{30\text{ft}}\right)\left(1+0.4\frac{6.2\text{ft}}{20\text{ft}}\right)\\ =16321.04{\text{lb/ft}}^2\times \frac{{10}^{-3}\text{kip}}{1\text{lb}}\\ =16.3{\text{kip/ft}}^2\end{array}$

Therefore, the value of net ultimate bearing capacity is $\underset{¯}{16.3{\text{kip/ft}}^2}$.