Design of Staircase and Flat Slabs

Contents

Recall various components of a Staircase.

A staircase is a set of steps used for vertical transportation between floors or levels in a building. The various components of a staircase include:

  1. Treads: The flat horizontal surface of each step, where a person places their feet when climbing or descending the staircase.
  2. Risers: The vertical surface that separates each tread.
  3. Stringers: The structural members that support the treads and risers. They are usually located on either side of the staircase and are typically made of steel or concrete.
  4. Balustrade: The railing system along the sides of the staircase that provides safety and stability. It can be made of various materials, such as wood, glass, or metal, and is supported by balusters.
  5. Balusters: The vertical posts that support the balustrade.
  6. Newel Posts: The larger, more robust posts that provide additional support to the balustrade and mark the beginning and end of the staircase.
  7. Handrails: The horizontal railing located at waist height on the sides of the staircase, which provides a handhold for stability while climbing or descending the staircase.
  8. Landings: The flat platform located between flights of steps. Landings provide a rest area and can also serve as a turning point for changing direction in the staircase.

Classify Staircase

Stairs are classified on the basis of their geometrical and structural configurations.

On the basis of their geometric configuration the stairs are:

  1. Single Flight/ straight stairs
  2. Quarter Turn
  3. Dog legged
  4. Spiral
  5. Helicoidal
  6. Straight stairs: Generally for small houses, available width is very retractable. So, this type of straight stairs are used in such conditions which runs straight between two floors. This stair may consist of either one single flight or more than one flight with a landing.
  7. Quarter turn stairs: A quarter turn stair is the one which changes its direction either to the right or to the left but where the turn is affected either by introducing a quarter space landing or by providing winders. In these types of stairs the flight of stairs turns 90 degrees at landing as it rises to connect two different levels. So it is also called the L-stair. Again these quarter turn stairs are two types
  8. Newel quarter turn stairs

These types of stairs have clearly visible newel posts at the beginning of flight as well as at the end. At the quarter turn, there may either be quarter space landing or there may be winders.

  1. Geometrical quarter turn stairs: In geometrical stairs, the stringer as well as the handrail is continuous without any newel post at the landing area.

3. Dog-legged stairs

Because of its appearance in sectional elevation this name is given. It comes under the category of newel stairs in which newel posts are provided at the beginning and end of each flight

4. Spiral Stairs:spiral stairs are usually made either of R.C.C or metal, and is placed at a location where there are space limitations. Sometimes these are also used as emergency stairs, and are provided at the back side of a building. These are not comfortable because all the steps are winded and provide discomfort.

5. Helical Stairs: A helical stair looks very fine but its structural design and construction is very complicated. It is made of R.C.C in which a large portion of steel is required to resist bending, shear and torsion.

Structural Configuration:

  1. Stair slab Opening Transverse: Transverse stairs are located remotely from each other and connect the two wings of the building. Wing stairs are one or two stairs located at the front and rear of each wing. Isolated stairs provide access limited to apartments served by the stairs and there is no access to other wings.
  2. Stair slab Opening Longitudinally: