In this article, we will discuss the overhanging beam.
The beam is a horizontal structural element made up of wood, steel, or concrete that resists the lateral load coming from the superstructure utilizing bending. It is expected to withstand shear force, lateral force, and bending moments.
There are different types of beams like Simply supported beams, Cantilever beams, Fixed beams, Continuous beams, Overhanging beams, etc.
2. Overhanging Beam
The overhanging beam is a type of beam in which the end proportion of the beam extends more from support. It is the combination of both a cantilever and a simply supported beam.
The overhanging beam is safe if you construct them in the right way. Otherwise, the beam may fail.
The overhanging beam is generally used to make balconies or shades. The extension in overhanging beam should be limited to 1m (3′-3”).
If there is a proper structural report suggesting an extension of more than 1m then it is ok to use.
2.1 Types of Overhanging Beam
a. Single Overhanging Beam
It is a simple type of beam in which a certain portion of the beam is extended beyond the support at one end only. It is the merge of simply supported and cantilever beams.
For example; a balcony that is being extended from the framed structure.
b. Double Overhanging Beam
The overhanging beam in which a certain portion of the beam is extended beyond the support at both ends is known as a double overhanging beam.
The load applied on the hanging portion is safely transferred to the support(i.e hinge or roller) by equivalent bending moment.
For example; a balcony that is being extended from the framed structure on both front and back or left and right.
3. Properties of Overhanging Beam
1. It should have enough strength to bear loads acting on it.
2. It should resist the chemical and weathering agencies.
3. It should be durable and sound.
4. It should have a width to depth ratio of more than 0.3.
5. Mininnium width should be 200mm.
6. The depth of overhanging should not be more than 1/4 of the clear span.
4. Uses of Overhanging Beam
An overhanging beam is used where it is not practical to provide support to the beam at one end or both ends.
The overhanging beam is mainly encountered in a floor beam that extends beyond the exterior wall of a building to provide support to a balcony.
5. Advantages of Overhanging Beam
1. This beam helps to provide balance to the axial moment at the support of the column.
2. It decreases the one-sided load in a beam.
3. It has low sagging.
4. It is simple to construct.
6. Disadvantage of Overhanging beam
1. It rises the dead load on the structure.
2. It rises the uniaxial moment at the support of the column.
3. Restriction in the extension length.
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