Question

Refer the dam section shown below. Which one of the following conditions represents the most stable state of the dam against rotation about its center of gravity? 

• A. T>3W and L<H
• B. Resultant force of T and W passes through the base of the dam
• C. H>3L and T = W
• D. Resultant force of T and W passes outside the base of the dam

Hint:

For a dam to be stable, the line of action of the resultant forces must pass through the base of the dam. This prevents overturning and ensures the dam remains upright.

Answer 1

The Correct Option is B

Step 1: Understand the Dam Stability Concept.
The stability of a dam is influenced by the forces acting on it, particularly the horizontal thrust (T) and the weight of the dam (W). For stability against rotation, it is crucial that the resultant of these forces passes through the base of the dam, ensuring no overturning moments.
Step 2: Identify the Key Conditions.
- The horizontal thrust (T) and the weight (W) must be balanced and pass through the base to avoid instability or tipping.
- L is the base length, H is the height of the dam, and CG is the center of gravity.
Step 3: Conclusion.
The condition for the most stable state of the dam is when the resultant of the forces T and W passes through the base of the dam, preventing tipping and ensuring stability.
Final Answer: \[ \boxed{\text{Resultant force of T and W passes through the base of the dam}} \]