What is the difference between braced and unbraced column?

Column is basically a vertical structure, which helps to transfer the load from top to bottom in a framed structure. Specifically columns transfer the compressive load from top floors, ceiling or beam to the foundation or to the beams. Braced column are the structural component, provided so as to resist the lateral forces. Bracing prevents buckling of column section. If we want to reduce the unsupported length of column, in such cases also its good to provide bracing in the structure. Bracing provides additional strength and stability to the structure.

Braced Columns

Structures which is subjected to lateral forces basically wind load and earthquake load, we resist this loads using bracing or any other structural component. So braced column is not designed to resist these . When the value of slenderness ratio along both the lateral dimension is less than 15, we should design it as a short column, or else as a long /slender column.

The different types of bracing are :

  • Single diagonal
  • Cross diagonal
  • K – bracing
  • V- bracing
  • Eccentric bracing

The main advantage of braced column is the sideways translation is negligible, thus the lateral sway is zero.

In earthquake prone areas we normally go for these types of columns.

Unbraced Column

Unbraced columns are basically those column which are designed to resist the lateral loads caused by wind load and earthquake loads. It has more serviceable area as compared to the braced columns structure. As it s easy to provide openings in braced columns structure. When the value of slenderness ratio along both the lateral dimension is less than 10, we should design it as a short column, or else as a long /slender column.

We go for unbraced columns, where the number of storeys is only 2 to 3 and also in less earthquake prone zones.

Column design

  • RCC Column Design is a free app for designing reinforced concrete columns as per Indian Standards.
  • RCC Design and detailing could be performed for uniaxial and biaxial bending conditions specified in IS456:2000
  • Option to save the design projects in local storage.
  • Detailed calculation steps presented for verification and validation.
column design android app

Check this post to read a brief about what is a column and what are the different types of column.

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