What Is Plinth Beam? – The plinth beam is a beam that is constructed to support the superstructure when the foundation is on piles. The building that is constructed between the ground floor level and ground-level portion of the building is known as the plinth beam.

The purpose of the construction of the plinth beam is it helps to transfer the live load and dead load that coming from the superstructure to the foundation. In a building when the foundation is suffering from settlement and required to prevent the extension of cracks above the walls, then the plinth beam is constructed.

As governed by the requirement, the plinth beam is not constructed less than 450 mm from the ground level and keeps it up 150mm above the road level. To keep the floor free from dampness a plinth beam is a construct that’s the plinth beam keeps the ground floor up from the ground level.
What are plinth beam and floor beam in construction? A plinth beam is a type of beam that is provided at the ground level in a framed structure and is also known as a Tie Beam as it holds the columns in place. The length and slenderness ratio of a column is reduced by using plinth beams.

Plinth beams are usually designed to withstand their own weight and the load of the masonry structure above them. They play an essential role in providing addon stability against building settlements and earthquakes. The plinth beam may not resist any of the load coming from the slabs. They need to be made strong enough to hold the columns in place but it is not necessary to always use reinforced concrete to construct them.

Plinth beams are primarily used to connect all the columns when the depths of the foundation are quite high. They also act as supplementary supports in avoiding differential settlement, maintaining the plinth plan properly and preventing difficulties in constructing walls.

Unlike plinth beams, ground beams are constructed at the foundation level to provide support to walls or joists when the soil subgrade has a low bearing capacity. Ground beams are usually built using reinforced cement concrete and prevent the settlement of walls by improving the bearing capacity of the soil.

: What are plinth beam and floor beam in construction?

What is plinth in building construction?

What is the meaning of the term “Plinth”? – The plinth can be defined as a level that comes above the ground level and just below the floor level. Plinth Beam: It is an R.C.C. beam constructed between columns. These are provided to support the walls. these beams help to avoid the settlement of walls that develop cracks in the structure.

What is plinth beam arrangement?

Features of Plinth Beam – — Plinth beam as mentioned are constructed at the foundation or the ground level. They act as tie beams at the plinth level, which finally will reduce the effective length of the columns. This arrangement tend to carry the wall load at the ground floor level to the columns, thus acting as as settlement controller.

Figure.2. Plinth Beam Arrangement

In situations, when there are different settlements, stresses cannot be taken completely by foundations. This would result in cracking in rubble foundation, and slowly creates cracking in the brick wall. Hence, the introduction of beam below these walls (plinth beams) helps to bear the additional tension, bending and shear forces.

This helps to minimize the cracking in the brick wall. The introduction of plinth beams carry the wall loads on the ground floor. The plinth beam size and reinforcement is designed based on the wall loading. In the case of low rise buildings, the loads from the floor beams are not transferred to the plinth beams.

Beams can be designed as plinth beam in these situation, by designing it as a normal beam taking into account the loads from the slabs. Plinth beams are a compulsory structural element in building wherever there are load bearing walls. It is mainly constructed using reinforced cement concrete.

What grade of concrete is used for a plinth beam?

What should be the Minimum Height for Plinth Beam? – The Plinth height lies between 300 mm to 450 mm (1 ft to 1.5 ft) from the natural ground level.

How many steel bars are required for plinth beams?

Two Reinforcement Steel bars with a minimum of 12mm diameter are required to be provided at bottom of a beam. However, at the top, 10mm diameter steel bars are recommended for the plinth beams.