Question

The holes left in permanent lining at the curb level to avoid development of hydrostatic pressure behind the lining due to water in shaft sinking are known as

• A. Product holes
• B. Weep holes
• C. Lining holes
• D. Drain holes

Hint:

The term "weep hole" is used widely in civil engineering for any opening that allows water to drain from behind a retaining structure, like a retaining wall, bridge abutment, or, in this case, a shaft lining.
The name itself suggests its function: allowing the structure to "weep" out trapped water.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks for the specific name of holes designed to relieve water pressure behind the lining of a mine shaft.

Step 2: Detailed Explanation:
When a shaft is sunk through water-bearing strata, water can seep into the space behind the permanent concrete or brick lining.
If this water is not drained, it will accumulate and exert a significant

hydrostatic pressure on the back of the lining.
This pressure can be strong enough to damage or even cause the failure of the shaft lining.
To prevent this, small-diameter holes or pipes, known as

weep holes, are intentionally left in the lining, typically at regular intervals.
These holes allow any trapped water to "weep" or drain out from behind the lining into the shaft, where it can be collected and pumped to the surface.
This relieves the hydrostatic pressure and ensures the stability of the shaft lining.

Step 3: Final Answer:
The holes designed for pressure relief behind a shaft lining are called weep holes.
This corresponds to option (B).