The effective span of a simply supported slab is the distance over which the slab is effectively supported by the underlying structure. It plays a crucial role in determining the design requirements and load distribution for the slab.



a) Distance between the centre of the bearing
b) Clear distance between the inner face of the wall plus twice the thickness of the wall
c) Clear span plus the effective depth of the slab
d) Both (A) and (C)



Distance between the centre of the bearing

The distance between the center of the bearing refers to the distance between the midpoint of the supports on which the slab rests. It is the clear span of the slab without considering the influence of the slab's effective depth on load distribution. This option alone does not account for the contribution of the slab's effective depth.

Clear distance between the inner face of the wall plus twice the thickness of the wall

This option considers the clear distance between the inner face of the supporting wall and adds twice the thickness of the wall. While this option includes the contribution of the wall thickness, it does not consider the slab's effective depth.

Clear span plus the effective depth of the slab

This option takes into account the clear span of the slab and adds the effective depth of the slab. The effective depth is the distance between the extreme compression fiber of the slab and the centroid of the tension reinforcement. This option considers both the clear span and the contribution of the effective depth, providing a more accurate measure of the effective span.

Both (A) and (C)

The correct answer is option D because it combines the advantages of both option A and option C. It considers both the distance between the center of the bearing (option A) and the clear span plus the effective depth of the slab (option C). By considering both factors, it provides a comprehensive measure of the effective span, taking into account the influence of both the bearing location and the slab's effective depth.

In conclusion, option D, which considers both the distance between the center of the bearing and the clear span plus the effective depth of the slab, is the correct answer for determining the effective span of a simply supported slab.