Calculation of loads for Column and Foundation Design | Structural Design

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How to calculate the total loads on a column and corresponding footing?

This article has been written on the request from my readers. Engineering students generally get confused when it comes to calculating loads for column and footings design. The manual process is simple.

Types of loads on column

  1. Self weight of the column x Number of floors
  2. Self weight of beams per running meter
  3. Load of walls per running meter
  4. Total Load of slab (Dead load + Live load + Self weight)

The columns are also subjected to bending moments which have to be considered in the final design. The best way to design a good structure is to use advanced structural design software like ETABS or STAAD Pro. These tools are leagues ahead of manual methodology for structural design, and highly recommended.

In professional practice, there are some basic assumptions we use for structural loading calculations.

You can hire me for your structural design need. Contact me.

For Columns

Self weight of Concrete is around 2400 kg per cubic meter, which is equivalent to 240 kN. Self weight of Steel is around 8000 kg per cubic meter. Even if we assume a large column size of 230 mm x 600 mm with 1% steel and 3 meters standard height, the self weight of column is around 1000 kg per floor, which is equivalent to 10 kN. So, in my calculations, I assume self weight of column to be between 10 to 15 kN per floor.

For Beams

Similar calculations as above. I assume each meter of beam  has dimensions of 230 mm x 450 mm excluding slab thickness. So, the self weight can be around 2.5 kN per running meter.

For Walls

Density of bricks varies between 1500 to 2000 kg per cubic meter. For a 6″ thick wall of 3 meter height and a length of 1 meter, we can calculate the load per running meter to be equal to 0.150 x 1 x 3 x 2000 = 900 kg which is equivalent to 9 kN/meter. You can calculate load per running meter for any brick type using this technique.

For autoclaved, aerated concrete blocks like Aerocon or Siporex, the weight per cubic meter is between 550 to 700 kg per cubic meter. By using these blocks for construction, the wall loads per running meter can be as low as 4 kN/meter, which can result in a significant reduction in the cost of construction.

For Slab

Assume the slab has a thickness of 125 mm. Now each square meter of slab would have a self weight of 0.125 x 1 x 2400 = 300 kg which is equivalent to 3 kN. Now, assume Finishing load to be 1 kN per meter and superimposed live load to be 2 kN per meter. So, we can calculate slab load to be around 6 to 7 kN per square meter.

Factor of Safety

In the end, after calculating the entire load on a column, please do not forget to add in the factor of safety. For IS 456:2000, the factor of safety is 1.5.

You can use RCC Column Design app to calculate steel required for the calculated axial load using this method.

59 thoughts on “Calculation of loads for Column and Foundation Design | Structural Design”

  4. Hi,

    Thanks for the useful information. I am totally new to this field and I have a couple of queries,

    1. How can I calculate the number of columns required for a building, say a building of two storeys of 2400 sq.ft?

    2. The size of the columns, the column footings size, the steel used in the column etc are dependent on the load on the columns. So should I calculate the total load of the building and distribute the load equally on the number of columns?

  7. Hi,

    I am going for construction of my own house – residential building with stilt + Ground+ 2 to 3 floors. The contractor is suggesting some measurements of foundation columns.

    Could you please let me know what are the measurements of columns in general for a building of above and the depth of the column should be.
    Thanks & Regards
    Balaji

    • Hello Balaji,
      I suggest you should hire a qualified Civil engineer for the job and not take structural based decisions yourself. This site is meant for people who are Civil engineers, civil engineering students, architects and architecure students and of course for people who are interested in gaining knowledge about structures.
      In no case is a layman allowed to take decisions regarding structural design. So please do consult a civil engineer and get the structural design. Every project is unique and needs designing accordingly.

      Thank you.

  9. hey i want design the building in my life time
    tell me what should i learn to become design Engineer atleast iwant to design one building in my lifetime provided should be safe

  12. hi madam, im civil engg im doing analysis in stad pro,pls can u tell me 1 ex after analysis whats the procedure to do the design

    pls tell formulas and tumb rules

    tank u

  17. m planning to build double storey house 17mx8m. Can u plis specify the number of coloumns to be erected and its sizes and also the beam sizes. Also the proper spacing of the coloumns. Bottom is open carport and level 1 is 2bedrooms,1m/bedrooms,kitchen,study rooms and small porch plus back porch as laundary areas.

    thnx

    • Well, that depends on the structural design. The steel design has to be appropriate. The span could go beyond 7m. It could be huge. 3m is the minimum distance between two supports.

  20. Dear sir,i want to know how to design the structural members….that means by keeping one buliding plan how to design the structural members i knw how to design by using problems types..but using one building plan how to design entire structural members ….i want to know the procedure with example plz hel me sir…kindly i request u

  22. wht dimension of raft foundation may be suitable for a three storey security building having floor area.14ft*12ft, having soil bearing capacity 150n/mm2..using m20 comcrete?

  23. dear madam can you help me with the formula of finding the depth of a foundation when given pressure as 23 ,weight of the soil as 423kg and the angle of repose 35degrees

  24. My friends new house was constructed on soft soil.the houes is g+1.it is rcc framed structure with isolated footing .the columns are 300x300mm .there are 20 column and spacing is 3mtr.in the first floor rcc slab roof is provided.footing of size 1.7*1.7mtr and 1.8 mtr deep was provided. 8nos 16mm dia rod is provided in columns .now after seeing some site on foundation design she is worried whether it is safe or not. kindly reply

  37. Hello,

    My company wants to build a new sign. It will be constructed of concrete footing. The sign will be 8x8x16 filled concrete blocks. I need help with calculating the footing size. Can you help me?

    Regards,

    Leonard

  39. Hi, thanks a lot for your information, now , how do i determine roof loads ( not slab type but of sheeting) that is transmitted to the columns? please help

  40. for making a sign board, i have calculated wind pressure and load. For heavy wind i calculated moment at the top of foundation. Now i want to know what is the equation to calculate the uplifting force (KN) / pullout or tension applicable on the footing by converting the bending moment to uplift force.

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