Design criteria
The design of beams is dependent upon the following
factors:
1. Magnitude and type of loading roof mat, flooring,
2. Duration of loading
3. Clear span 6m, 7, 8, 9
4. Material of the beam
5. Shape of the beam cross-section rectangular, square, t beam, hollow beam
Load on column, Beam & Slab:
1) Column Self Weight X Number of floors
2) Beams Self Weight per running meter
3) A load of walls per running meter
4) The total load on Slab (Dead load + Live load + Self-weight)
Besides this above loading, the columns are also subjected to bending moments that have to be
considered in the final design.
The most effective method for designing structure is to use advanced structural design software like
ETABS or STAAD Pro. These tools are reduced laborious and consuming method of manual calculations
for structural design, this is highly recommended nowadays in the field. for professional structural design
practice, there are some basic assumptions we use for structural loading calculations.
Quantity For Slab
1. Load Calculation on Column (Column Design Calculations):
we know that the Self-weight of Concrete is around 2400 kg/m3, which is equivalent to 240 kN and the
Self-weight of Steel is around 8000 kg/m3.So, if we assume a column size of 230 mm x 600 mm with 1% 1.5 % ang
gamit
steel and 3 meters standard height, the self-weight of the column is around 1000 kg per floor, that id
equal to 10 kN.
Volume of Concrete = 0.23 x 0.60 x 3 =0.414m³
Weight of Concrete = 0.414 x 2400 = 993.6 kg
Weight of Steel (1%) in Concrete = 0.414x 0.01 x 8000 = 33 kg
Total Weight of Column = 994 + 33 = 1026 kg = 10KN
While doing column design calculations, we assume the self weight of columns is between 10 to 15 kN
per floor.
2. Beam Load Calculation:
We adopt the same method of calculations for beam also.we assume each meter of the beam has
dimensions of 230 mm x 450 mm excluding slab thickness.Assume each (1m) meter of the beam has
dimension
230 mm x 450 mm excluding slab.
Volume of Concrete = 0.23 x 0.60 x 1 =0.138m³
Weight of Concrete = 0.138 x 2400 = 333 kg
Weight of Steel (2%) in Concrete = = 0.138 x 0.02 x 8000 = 22 kg
Total Weight of Column = 333 + 22 = 355 kg/m = 3.5 KN/m
beam
So, the self-weight will be around 3.5 kN per running meter.
3. Wall Load Calculation:
hollow blocks here
we know that the Density of bricks varies between 1500 to 2000 kg per cubic meter.For a 6 inch thick
Brick wall of 3-meter height and a length of 1 meter,The load / running meter to be equal to 0.150 x 1 x 3
x 2000 = 900 kg,which is equivalent to 9 kN/meter.This method can be adopted for load calculations of
Brick per running meter for any brick type using this technique
.For aerated concrete blocks and autoclaved concrete blocks, like Aerocon or Siporex, the weight per
cubic meter is between 550 to 700 kg per cubic meter.if your are using these blocks for construction, the
wall loads per running meter can be as low as 4 kN/meter, use of this block can significantly reduce the
cost of the project
4. Slab Load Calculation: d = 1 m, thickness is 1.5 m
Let, Assume the slab has a thickness of 125 mm. So, the Self-weight of each square meter of the slab
would be= 0.125 x 1 x 2400 = 300 kg which is equivalent to 3 kN .Now, If we consider the Finishing load
to be 1 kN per meter and superimposed live load to be 2 kN per meter.
tiles, marbles tao
So, from the above data, we can estimate the slab load to be around 6 to 7 kN per square meter.
5.The Factor of Safety:
In the end, after calculating the entire load on a column, do not forget to add in the factor of safety,
which is most important for any building design for the safe and convenient performance of the building
during his design life duration.This is important when Load Calculation on Column done.
As Per IS 456:2000, the factor of safety is 1.5.
