estimation of pad foundtaion sizes

[PhoenixP]

i want to estimate the size of foundation of equal sides
and 1m deep required to resist overturning with various safety factors . i know the overturning moment induced in the middle of the foundation and can therefore estimate the restoring moment required
is there an easy way to calculate (estimate) the size
of foundation needed?

 

[hokie66]

Statics, with a bit of trial and error.

 

[msquared48]

Tributary area to the foundation element in question. Very rough, but good for estimating.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[PhoenixP]

T & E? what no easy formula?

 

[msquared48]

On second thought here, it sounds like a retaining wall analysis. There are formulas and design procedures in most Civil and Structural textbooks, to include the reinforced concrete design.

There is no one formula. There are many neede, plus the knowhow in how to properly use them.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[hokie66]

I think the best way is to do it in reverse and prepare yourself tables. Take your 1000 deep footing, then increment plan dimensions by 200, apply gravity (and uplift) loads, compute allowable overturning moment for each size.

 

[csd72]

PhoenixP,

You need to check overturning, bearing and sliding.

If it was easy then you would not need an engineer to do it.