What sort of soil pressure checks do I need to do for footing?
What sort of soil pressure checks do I need to do for footing?
(OP)
Hi, everyone. I am designing a silo footing, say 18 ft x 18 ft, and 2 foot thick. There is a 58 foot tall silo on my footing. Forces acting on my footing include the dead and live loads of the silo. I have wind and seismic loads on my silo, too, resulting in base shear and overturning moments on my footing.
I am checking the adequacy of the footing, and so far have checked stability and sliding. F.S. for stability is >1.5 and for sliding is >2, so both are OK.
My question is what sort of soil pressure checks do I need to do on my footing? What load cases do I need to consider? So far, I have checked DL + LL. I understand I need to do DL + WL, and DL + EQ, too, is that correct?
Also, what is the purpose of calculating the eccentricity, e, locating the kern, and then finding the values for the coefficients C1 and C2?
I am checking the adequacy of the footing, and so far have checked stability and sliding. F.S. for stability is >1.5 and for sliding is >2, so both are OK.
My question is what sort of soil pressure checks do I need to do on my footing? What load cases do I need to consider? So far, I have checked DL + LL. I understand I need to do DL + WL, and DL + EQ, too, is that correct?
Also, what is the purpose of calculating the eccentricity, e, locating the kern, and then finding the values for the coefficients C1 and C2?
kk88818
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RE: What sort of soil pressure checks do I need to do for footing?
2. Minimize the unfavorable effects due to bending and rotation of the footing. (no idea about C1 & C2 coefs)
RE: What sort of soil pressure checks do I need to do for footing?
The eccentricity (M/P) will determine the soil pressure distribution under the footing.
If e =M/P <L/6, the soil pressure is trapezoidal.
If e =M/P =L/6, the soil pressure is triangular
If e >L/6, the soil pressure is triangular
Get a good structural concrete textbook and look up footings under eccentric column loads.
RE: What sort of soil pressure checks do I need to do for footing?
RE: What sort of soil pressure checks do I need to do for footing?