Reinforcement detailing of Columns from ETABS output

CHALLENGE 08

Aim:- To provide,

• The details of longitudinal reinforcement for the two columns (3A & 3B), from foundation to terrace level.
• The details of shear reinforcement as per special confining reinforcement provision of clause 8.1 of IS 13920 - 2016.

Introduction:-

• A reinforced concrete column is a structural member designed to carry compressive loads, composed of concrete with an embedded steel frame to provide reinforcement.
• For design purposes, the columns are separated into two categories: short columns and slender columns.
• A short column is a structural member whose relatively short length virtually ensures it will fail in compression if it is evenly loaded along its axis.
• Columns can be classified as short, intermediate, or long, depending on their lengths, their material properties, and the lengths of other columns in the same structure.
• A slender column is a thin column. For any construction, foundation starts with marking the position of columns and then their design and analysis.
• Slender column can be tested in laboratory to observe the action of buckling or cripping. For a column,based on slenderness ratio, it is termed as long or short column.

Procedure:-

Step1:-

• This model is given in the question itself
• Open this model by using a ETABS

Step2:-

• After opening the model then select the column
• To select the column drag a mouse then the column will be selected

Step3:-

• After selecting the 2 columns
• Then click a right button of your mouse.
• Then click on the show selected objects only option.
• Then the selected column only appear in the screen.

Step4:-

• After selecting the column, then click on Run analysis in ribbon menu.
• Click on Run analysis or use a F5
• Make sure that the correct column is selected which has given in the question.

Step5:-

• After the completion of analysis, then go to the concret frame design for further process.
• Click on the concrete frame design
• Then wait for some times then it will show the details of the model

Lateral reinforcement and shear reinforcement of column at Grid A-3

Lateral reinforcement and shear reinforcement of column at Grid B-3

Storey assignment tab to refer elevation of column

Special confining reinforcement from IS 13920-2016 (Clause 8.1)

From the IS 13920-2016 mentioned about the lo , confinement spacing and amount of confinement rebar do not less than

1. Larger column dimension
2. 1/6th of the clear span of the column
3. 450mm

Here the larger column dimension is 650mm.

In the 1/6th of clear span

• Column size is given as 450x650mm
• In this model, I'm considering first floor height which is a 4m.
• The height is given from the center of the column to the center of the other column
• We have to deduct the half of the beam depth

• Deduct the 150mm above and below as shown in fig., then we get the height of the column as 3700mm
• 1/6 * 3700 = 616mm

Hence highest value will taken, so take 650mm which is a larger column dimension.

Confinement spacing

Confinement spacing not more than

• 1/4 of smaller column dimension

1/4*450 = 112.5

• 6 times dia of the column

6*8 = 48

• 100mm

Column 450x650mm which I have provided the 25mm dia bar throughout the column

This is the snap shot for 1 floor which I have provided the 25mm dia bar throughout the column

Cross section of column which I have provided the 25mm dia bar throughout the column

longitudinal section of column which I have provided the 25mm dia bar throughout the column

Column 450x650mm which I have provided the 32mm and 25mm dia bar at the column in 450mm direction

This is the snap shot for 1 floor which I have provided the 32mm and 25mm dia bar the lapping area occured at the column in 450mm direction

Cross section of column which I have provided the 32mm dia bar upto first floor and 25mm dia bar throughout the column after 1st floor in 450mm direction

Cross section of column which I have provided the 25mm dia bar throughout the column after 1st floor in 450mm direction

Longitudinal section of column which I have provided the 32mm dia bar upto first floor and 25mm dia bar throughout the column after 1st floor in 450mm direction

Column 450x650mm which I have provided the 32mm and 25mm dia bar at the column in 650mm direction

This is the snap shot for 1 floor which I have provided the 32mm and 25mm dia bar the lapping area occured at the column in 650mm direction

Cross section of column which I have provided the 32mm dia bar upto first floor and 25mm dia bar throughout the column after 1st floor in 650mm direction

Cross section of column which I have provided the 25mm dia bar throughout the column after 1st floor in 650mm direction

Longitudinal section of column which I have provided the 32mm at first floor and 25mm dia bar throughout the column after 1st floor in 650mm direction

So we should take a 100 mm which is a max value

Ash = 720mm^2 (This value is taken from the ETABS)

Result:-

• The ETABS model hass been analysed after checking the model.
• The concerete frame design also be carried out.
• The longitudinal reinforcement and shear reinforcement details obtained by the ETABS result has been drafted in the AutoCAD.
• The given Grid along A-3 column and Grid along B-3 column has successfully designed and analysed by using ETABS.