Question: A strip footing is placed on a sandy soil with a friction angle of 30 degrees. What is the approximate value of the bearing capacity factor N_q?

Options:

1. 1.5
2. 2.5
3. 3.5
4. 4.5

Correct Answer: 3.5

Solution:

For a friction angle of 30 degrees, the bearing capacity factor N_q can be approximated using the formula N_q = e^(π * tan(φ)) * tan(45 + φ/2). For φ = 30 degrees, N_q is approximately 3.5.