Some vital thumb rules to avoid wrong structural design

RCC columns should be designed based on the total load on the columns. But there are also few thumb rules which the architects should follow so that no mistakes occur at the time of settling the approximate place for columns.

The details of these thumb rules are given below :-

Size of the columns
Distance among columns
Alignment of columns

Size of the columns

The size of the columns is based on the total loads enforced on the columns. The lowest size of the column should not be under 9" x 9".
9" x 9" columns should be utilized for a single storey structure having M15 grade of concrete.
In case, 9" x 9" column size is required to be applied for 1 and half storey structure, then it is recommended to apply M20 grade concrete.
A secure and structurally strong column size for a 1 and half storey structure should not be under 12"x9" with M15 grade concrete.

Distance among the columns

It is suggested to keep equivalent distance among the centers of two columns. The layout of a column should be organized on a grid.
The distance among two columns with size 9" x 9" should not surpass 4 meter center to center of the column.
If it is necessary to provide bigger barrier free distances, then bigger column size should be utilized.

The size of the columns is expanded owing to the factors given below :-

Growth in the distance among two columns (It expands the dimensions of the columns and the depth of the beam).
Height of the building (Rise in the number of floors is directly proportionate to the dimensions of the columns).

Alignment of the columns

A rectangular grid should be formed for arranging the columns. It aids in eliminating mistakes and the placement of the columns becomes perfect.

The columns are preferably placed in the following ways :-

In a straight line with the use of a grid.
In a circular manner for circular buildings.

Zigzag placing of columns is completely wrong process for preparing structural design. It should be kept in mind that when columns are constructed, beams are placed connecting the columns.

The following problems may occur for zigzag column placement :-