Difference between Braced and Unbraced Column
Concept about Braced columns
The braced columns are the structural columns of the construction structure, which have been designed to resist the lateral loads of the construction structure. The steel or RCC has been used to build the braced columns, and sometimes, other types of structural elements, including beams and girders, have been used to construct the braced columns.
The braced columns have been connected to the construction structure with the help of the bracing system. This helps distribute the entire load of the construction structure and also maintains its stability. The braced columns help to prevent the buckling of the column.
Effectiveness of using braced columns
➢ By using the braced columns, the risk of lateral storey displacement, bending moment in the columns, or the incidence of storey drift has been reduced.
➢ In the case of the reduction of the lateral displacement, the use of X-bracing is more effective as compared to the use of V-bracing.
➢ The seismic forces and wind forces can be resisted by using the braced columns.
➢ The installation of the steel bracing is economical as well as easy to erect. The braced columns also consume less space and have higher flexibility, which helps to achieve appropriate strength and stiffness.
Different types of braced columns
Different types of braced columns are used in the construction site, which include:
Single diagonal
This type of braced column has been used in short columns and has been placed at a 45-degree angle to the column.
Cross diagonal
This type of braced column helps to connect two or more columns together. In this case, the diagonal braces have been placed in a perpendicular or cross-like pattern.
Eccentric bracing
This type of bracing has been connected to an offset location.
Knee bracing
The knee bracing is also used in the short columns, in which the bracing has been connected at an angle which forms a knee-like shape.
X-bracing
The X-bracing has been used in the tall column, in which the two diagonal braces have been placed in an X-shape. This type of bracing helps to provide lateral stability to the construction structure.
V- bracing
In this type of bracing, the diagonal braces have been placed in a V-shape.
Concept about unbraced columns
The unbraced column is the vertical structural element of the construction structure. The unbraced column does not provide any kind of lateral support to the construction structure. The unbraced columns have been designed only to support the axial load of the construction structure. Any kind of bending forces cannot be supported by the unbraced columns. In that construction structure, where the columns have been subjected to only the axial loadings, the unbraced columns are used.
The unbraced columns have more serviceable areas. The unbraced columns are shorter and thicker. Due to this, the unbraced columns have been used in that building structure where the storey number is 2 to 3, and also it has been used in that building structure which is located in less earthquake-prone zones.
Key differences between braced and unbraced columns
➢ The columns have been considered as the braced columns in the case of the lateral stability of the construction structure, which is provided by the walls. On the other hand, the columns have been considered as the unbraced columns, in the case of the lateral stability of the building structure, which is provided by the columns.
➢ The braced columns have the ability to resist the lateral loads, including earthquake, wind forces and others. In this case, the size of the columns has been optimised. In the case of the unbraced columns, the lateral loads have been supported by those columns which are heavy and large in size.
➢ In the case of the braced columns, the joint translation or sideways movement is not possible. On the other hand, in the case of the unbraced columns, the sideways or joint translation has occurred to a large extent.
➢ The braced columns have been used to design the steel structures, whereas the unbraced columns have been used to design the RCC structures.
➢ In addition, the braced columns have the capability to resist the incidence of earthquakes, whereas the unbraced columns have less capability to resist earthquakes.
➢ In the context of the braced columns, difficulty has been faced while providing the opening between the two braced columns. On the other hand, the provision of the opening between two unbraced columns is relatively easy as compared to the braced columns.
➢ In case of the tube structures of the multi-storey buildings, the use of braced columns has been seen. On the other hand, in the case of the RCC-framed structures on the low-storey buildings, the use of unbraced columns has been seen.
➢ In the case of the braced columns, there is a connection between the braced columns and the beam of the construction structure. On the other hand, the columns are not connected to any structure, as this is a free-standing column.
➢ By using the braced columns, the strength and stiffness of the buildings have been increased. On the other hand, by using the unbraced columns, the overall stiffness and strength of the building are less than the braced columns.
To learn more, watch the following video tutorial.
Video Source: KaaShiv InfoTech Jobs
➢ The load-resisting capacity of the braced columns against the sidesway is larger than the unbraced columns. The braced columns have been reinforced by the steel members, which helps to enhance the tensile and compressive strength of the building structure.
