column and it's types

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WHAT IS COLUMN?

Group members1-M. Ismail Joiya2- M.Adnan doger3-M.Asif4-Tariq Rasool5-Sajjad Ahmad6-Irfan Hussan

WHAT IS COLUMN?

Column is a vertical structural member. It transmits the load from ceiling/roof slab and beam, including its self-weight to the foundation. Columns may be subjected to a pure compressive load. R.C.C. columns are the most widely used now-a-days.

ColumnsColumns carry primary Axial Loads and therefore are designed for compression.Additional loads from snow, wind or other horizontal forces can cause bending in the columns.Columns then need to be designed for Axial Load and Bending.

ColumnsLongitudinal rebar runs vertically and is held in place by tiesLongitudinal bars are typically about 4% of the gross column area; ties are usually #3 or #4 barsTypically designed for compression, but must be able to resist bending

Photo courtesy of John Gambatese

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Column Forces F (External)WCOL (External)

R1 (Internal)R2 (Internal)RSoil (External)

WFTG(External)

Horizontal loads caused by wind, snow, seismic or internal building load

Structural EngineeringCivil Engineering and Architecture CourseUnit 6 Lesson 6.1 Intro to Structural Engineering

Project Lead the WayCopyright 2005

6Column loadings , horizontal loads cause bending in the column while axial loads cause compression loads.

COLUMN LOAD TRANSFER FROM BEAMS

Types Of ColumnsLong ColumnsShort (Strut) ColumnsIntermediate Columns

Long Column Whenthe ratioof effective length tothe leastradius of gyration is greater than 45, then it is called a long column.

A long column is subjected to bending moment inadditionto direct compressivestress.

The load carrying capacity of a long column is less than a short column

The load carrying capacity of a long column depends upon slenderness ratio (slenderness ratio increases then the capacity of the column decreases)

LONG COLUMN :When length of column is more as compared to its c/s dimension, it is called long column.Long Column Le/rmin > 50Where,Le = effective length of columnrmin = Minimum radius of gyration

Real world example:Here in picture we can see long columns on front of building in The White house Washington D.C(USA).

Short Column:

Whenthe ratioof effective length tothe leastlateral dimensions of the column is less than 12, then it iscalled a short column.

(or)Whenthe ratioof effective length tothe leastradius of gyration is less than 45, then it is called a short column

SHORT COLUMN :When length of column is less as compared to its c/s dimension, it is called Short column.Short Column Le/rmin