For stairs spanning horizontally, the minimum waist provided is

Solution(By Examveda Team)

In RCC structures design, the waist of stairs refers to the thickness of the waist slab or the thickness of the slab connecting the treads and risers. This thickness is crucial for providing the necessary structural stability and load-bearing capacity to the stairs.

According to standard design practices and codes, the minimum thickness of the waist for stairs spanning horizontally is typically considered to be 6 cm. This thickness ensures adequate strength and durability of the stairs to withstand imposed loads and maintain user safety.

Therefore, Option B: 6 cm is the correct minimum waist thickness for stairs spanning horizontally in RCC structures design. While some variations might exist based on specific design requirements and local building codes, the generally accepted standard is 6 cm for such scenarios.