Posts Tagged Thumb rules for making a column layout
Column Layout for a residence using the Thumb rules| Building Construction
In my earlier article, we discussed three important thumb rules that are to be followed while making a column layout for any building. They are as follows:
In this article, we will see an example of a residence of which column layout is done keeping the above three thumb rules in mind.
Column Layout for a residence
The residential villa comprises of 1 and half floors. Initially, the column size 9″x12″ had been used with the use of M15 grade of concrete. The builder wanted to save on his budget by making the columns smaller in size. That is why, the columns in the Floor plans below are 9″x9″ in size but the Engineer made sure that M20 grade of concrete would be used for Columns.
Guidelines to be followed for making a column layout
In this article, we will go through the essential thumb rules to be followed for giving a column layout. Ofcourse columns have to be designed in accordance to the total forces acting on the structure, but apart from that, it is essential for every Civil engineer and Architect to remember a few thumb rules so that they are prevented from making mistakes.
Three thumb rules to be followed are as follows:
- Size of the Columns
- Distance between Columns
- Alignment of columns
Minimum Size of RCC columns
The size of the columns depends on the total load on the columns. There are axial loads and lateral loads. Large beam spans induce bending moment not only in the beams, but also in columns which are pulled by the stresses in the beams. It is important to use advanced structural design software like ETabs or Staad pro. I highly recommend every structural designer learn these software. The thumb rules are for general designing in very small projects.
For this general thumb rule, we will assume a structure of G+1 floors high, using standard 6″ walls.
Minimum size of an RCC column should not be less than 9”x 9” (225mm x 225mm) with 4 bars of 12 MM Fe500 Steel.
These days the minimum I use in my projects is 9″ x 12″ (225 mm x 300mm) with 6 bars of 12 MM Fe500 steel. You can never go wrong with strong columns. I also recommend use of M20 grade concrete for the structure (ratio 1 part Cement : 1.5 parts Sand : 3 parts Aggregate with 0.5 parts water by volume). I recommend use of 8 MM stirrups at a distance of 150 MM center to center throughout the length of column.
This setup of 9″ x 12″ RCC columns is safe for G+1 Floors. There are a lot of other considerations, but this is just a thumb rule.