Reinforcement detailing of Columns from ETABS output

Reinforcement detailing of columns in Etabs 2018.

The ETABS file for a G+4 building is provided. Run the analysis and design the RCC Moment Resisting Frame. The following challenge deals specifically with two columns at the following grid intersections.

1. 3A
2. 3B

• Provide details of longitudinal reinforcement for the two columns, from foundation to terrace level. Sketch the column cross sectional & elevation details or draft it using autocad software.
• Show shear reinforcement & lapping details as per special confining reinforcement provision of clause 8.1 of IS 13920 - 2016.

Aim:

• To provide details of longitudinal reinforcement for the two columns (3A & 3B), from foundation to terrace level.
• To provide 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:

• open it in the etabs(the challenge data is same as the previous one).
• now click on concrete Frame desing and set output as longitudinal reinforcing as shown below.
• now go to elevation and set on 3.

• The following results will be as displayed by Etabs.

GRID 3A:

• From Base to first floor the maximum Ast is = 7027 mm^2.
• So we can provide 8 bars of 32mm = 9 x 803.84

=6446.72 mm^2.

• 2 bars of 16mm =2X200.96

=401.92

=7048.72 mm^2.

• Therefore as per calculation the area fits within entire span.+

GRID 3B:

• From Base to Terrace the maximum Ast is = 5046 mm^2
• 7 bars of 28mm = 7x615.44

=4310 mm^2

• 3 bars of 20mm = 3x314

=5250.8 mm^2

• Therefore as per calculation the area fits within entire span..

Shear reinforcement:

• now click on concrete Frame desing and set output as shear reinforcing as shown below.
• The following results will be as displayed by Etabs.

RESULT:

• The longitudinal reinforcement for two column at grid intersections (3A and 3B) detail is provided.
• The shear reinforcement & lapping details as per special confining reinforcement provision of clause 8.1 of IS 13920 - 2016 is provided.