Which of the following assumptions made in the Terzaghi’s bearing capacity theory?
- AThe base of footing is rough
- BThe footing is shallow
- CThe shear strength of soil is governed by the Mohr-Coulomb equation
- DAll of the aboveCorrect
Solution
Concept
Assumptions in Terzaghi bearing capacity theory
Formula
NONE
Step-by-step solution
1. Terzaghi’s bearing capacity theory assumes the footing depth is less than or equal to its width (shallow foundation). 2. It assumes the base of the footing is rough, preventing lateral movement of soil directly under the base. 3. It assumes the shear strength of soil is governed by the Mohr-Coulomb equation. 4. Therefore, all of the listed options are assumptions made in Terzaghi's theory. Answer: D
Explanation
Terzaghi's bearing capacity theory relies on several simplified assumptions to determine the ultimate load-bearing capacity of soil. It assumes that the base of the footing is rough, the footing is shallow with depth less than or equal to its width, and soil shear strength obeys the Mohr-Coulomb failure criterion. Therefore, all of the listed conditions are valid assumptions within the theory.
Why the other options are wrong
A) Roughness of the footing base is only one of several assumptions in Terzaghi's theory. B) Shallow footing depth is only one of the key assumptions in Terzaghi's theory. C) Mohr-Coulomb failure criterion is only one of the governing assumptions in Terzaghi's theory.
Shortcut
Terzaghi's bearing capacity assumes rough base, shallow footing, and Mohr-Coulomb criteria.
Common mistake
Assuming Terzaghi's theory considers a smooth footing base like Rankine's theory rather than a rough base.
Correct answer: D) All of the above