Question

Which one of the following ropes cannot be an effective cable bolt?

• A. Locked coil wire rope
• B. Lang's lay wire rope
• C. Ordinary lay wire rope
• D. Bird-caged wire rope

Hint:

Effective cable bolts require \[ \boxed{ \text{Good flexibility and strong grout bonding.} } \] Locked coil wire ropes provide poor grout interlocking.

Answer 1

The Correct Option is A

Step 1: Recall the requirement of cable bolts. Cable bolts require good flexibility and adequate bond with grout so that the load is effectively transferred to the surrounding rock.

Step 2: Identify the unsuitable rope. Locked coil wire ropes have a smooth outer surface, resulting in poor bonding with grout. Hence, they are not effective as cable bolts. Therefore, \[ \boxed{\text{Locked coil wire rope}} \] is the correct answer. Hence, \[ \boxed{(A)} \] is the correct answer.