Calculation of Effective Soil Pressure

Problem: A RCC footing is to be constructed 6 ft below the grade. If allowable soil pressure is 5 ksf and self weight of soil is 100 pcf. What will be the effective soil pressure
at the bottom of footing, if depth of footing is 20"?
Exam Name: West Region Gas Company Ltd. 2014


Solution:

Weight of footing =(20/12) *150
                             = 250 psf

Weight of soil on the top of footing
                             = {6 - (20/12)} *100
                             = 433 psf


Effective soil pressure at the bottom of the footing,
                             = 5000 - 250 - 433
                             = 4317 psf
                             = 4.13 ksf (Answer)

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