Question

Match List I with List II 

Choose the correct answer from the options given below: 
 

• A. A - IV, B - I, C - II, D - III
• B. A - I, B - IV, C - II, D - III
• C. A - III, B - II, C - I, D - IV
• D. A - IV, B - II, C - III, D - I

Hint:

To easily remember the structural mechanics:
- Apron $\leftrightarrow$ Uplift (seeping water pushes upward from below).
- Walls $\leftrightarrow$ Earth Pressure (retaining walls hold back soil).
- Foundation $\leftrightarrow$ Contact Pressure (transfers weight to the ground).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Designing hydraulic structures (such as drop spillways and check dams) requires analyzing the different structural components and the specific physical forces acting on them.
Detailed Explanation:
Let us match each structural component with its primary design force:
- A. Apron thickness: Water seeping underneath a hydraulic structure creates an upward force.
This upward force, known as piping or uplift pressure, can lift and crack the apron.
The apron must be made thick and heavy enough to resist this force.
This matches with IV. Uplift pressure.
- B. Side walls: The retaining side walls hold back the earthen banks of the channel.
They must be designed to withstand the lateral forces exerted by the soil.
This matches with I. Earth pressure.
- C. Foundation: The foundation transfers the weight of the entire structure to the soil underneath.
It must be designed to distribute this load safely, keeping the contact pressure below the soil's bearing capacity.
This matches with II. Contact pressure.
- D. Head wall: The head wall stands perpendicular to the water flow, acting as a dam.
It must withstand the pressure exerted by the pooled water behind it.
This matches with III. Hydrostatic pressure.
Combining these pairs gives the sequence: \[ \text{A - IV}, \ \text{B - I}, \ \text{C - II}, \ \text{D - III} \] This matches Option (A).

Step 2: Final Answer:
The correct matching sequence is A - IV, B - I, C - II, D - III.