I'm curious if many of you have been given design criteria from geotechnical engnineers that specify a maximum and minimum soil pressure outside the state of Colorado?
If so, how do many of you design the footings when you can not meet the maximum or the minimum?
For example: you have a maximum of 3,000psf and minimum of 1,000psf soil bearing and you have to design a 12" deep square footing for a column load of 10,240lbLL and 2,560lbDL. Say you run with a 2'-0" square pad, which gives you a max load of 12,000lb and a min of 4,000lb. I have a total load of 13,400lb (600lb for footing) and a dead load of 3,160lb. I fail at the max and the min.
I know I can increase the size of the footing, maybe a 2'-3" square pad and then increase the depth to gain dead load. But this is for a residential single family house were cost of excavation and materials needs to be kept to a minimum. I welcome any advice.
If so, how do many of you design the footings when you can not meet the maximum or the minimum?
For example: you have a maximum of 3,000psf and minimum of 1,000psf soil bearing and you have to design a 12" deep square footing for a column load of 10,240lbLL and 2,560lbDL. Say you run with a 2'-0" square pad, which gives you a max load of 12,000lb and a min of 4,000lb. I have a total load of 13,400lb (600lb for footing) and a dead load of 3,160lb. I fail at the max and the min.
I know I can increase the size of the footing, maybe a 2'-3" square pad and then increase the depth to gain dead load. But this is for a residential single family house were cost of excavation and materials needs to be kept to a minimum. I welcome any advice.