The live load and dead load in a three storeyed residential building, transferred through a single column

Q. The live load and dead load in a three storeyed residential building, transferred through a single column, is 12 tons and 18 tons respectively. If the soil bearing capacity is 10 ton/sqm and the factor of safety is 1.5, the area of column footing is sqm

Ans: 4.0 to 5.0

Sol:

Given, Live load = 12 ton. Dead load = 18 ton.
Total load = 30 ton.
Factor of Safety = 1.5.
Thus, Factored total load = Factor of Safety × Total Load = 1.5 × 30 = 45 ton.
Soil bearing capacity is 10 ton/m².
Area of Column footing