Cut-off (termination) distance in bundled bars Four 30 mm bars are bundled; the lower two continue to the end supports. Keep the distance between the cut-off points of the upper bars equal to:

Introduction:
Bundled reinforcement is used to accommodate large steel areas within limited beam width. When bars in a bundle are curtailed at different locations, codes specify minimum stagger distances between bar end points to avoid abrupt changes in stiffness and bond demand.

Given Data / Assumptions:

• Bundle of 4 bars, diameter 30 mm each.
• Lower two bars continue to end supports (not curtailed).
• Upper two bars are curtailed and must terminate at separated points.

Concept / Approach:
Staggering bar cut-offs ensures that anchorage forces are distributed and splitting cracks are limited. A typical prescriptive minimum stagger for heavy bars in a bundle is about 0.75 m along the member length, preventing simultaneous loss of steel area over a very short region.

Step-by-Step Solution:
1) Identify that two bars in the bundle are to be curtailed.2) Apply the minimum longitudinal stagger rule for bundled bar cut-offs.3) Provide at least 0.75 m between successive cut-off points.4) Detail adequate development length beyond theoretical cut-off sections.

Verification / Alternative check:
Stagger distances of ~0.75 m are widely adopted in detailing guides to mitigate bond stress concentration.

Why Other Options Are Wrong:
Zero defeats the purpose of staggering; 0.9 m and 1.2 m are conservative but not the standard minimum asked; selecting the code-typical minimum 0.75 m is correct.

Common Pitfalls:
Ending multiple bars at the same section; omitting hooks/anchorage; ignoring shear and moment envelopes when choosing curtailment.

Final Answer:
0.75 m