Rectangular Concrete Tank: Stability Forces
Rectangular Concrete Tank: Stability Forces
(OP)
I am reviewing the sliding stability of a 16'x14'x17'-deep concrete tank. Essentially, it will need to behave as a retaining wall during a possible future installation of an adjacent tank. There will be full height soil on one side and full excavation on the opposite side of the tank.
When I check the sliding stability for this case I get a S.F. = 0.74. Increasing the slab doesn't add enough weight to increase the S.F. by much.
I am hoping to use the friction between the soil and the SIDEWALLS to help pump-up my S.F. > 1.5. However, I can't find any information concerning how to adequately calculate this resistance.
My guess would be to use the Friction Angle for Dissimilar Materials from AASHTO (typically used in calculating the vertical component of Coulomb lateral earth pressures) to get a corresponding friction coefficient for the walls. Then, multiply the linearly varying lateral soil pressure normal to the sidewalls of the tank to get a linearly varying friction resistance for the orthogonal direction.
Thoughts? Thanks!
When I check the sliding stability for this case I get a S.F. = 0.74. Increasing the slab doesn't add enough weight to increase the S.F. by much.
I am hoping to use the friction between the soil and the SIDEWALLS to help pump-up my S.F. > 1.5. However, I can't find any information concerning how to adequately calculate this resistance.
My guess would be to use the Friction Angle for Dissimilar Materials from AASHTO (typically used in calculating the vertical component of Coulomb lateral earth pressures) to get a corresponding friction coefficient for the walls. Then, multiply the linearly varying lateral soil pressure normal to the sidewalls of the tank to get a linearly varying friction resistance for the orthogonal direction.
Thoughts? Thanks!






RE: Rectangular Concrete Tank: Stability Forces
RE: Rectangular Concrete Tank: Stability Forces
RE: Rectangular Concrete Tank: Stability Forces
Maine Professional and Structural Engineer
American Concrete Industries
www.americanconcrete.com
RE: Rectangular Concrete Tank: Stability Forces
RE: Rectangular Concrete Tank: Stability Forces
It does seem like this type of shear resistance should be allowed to be used though. When I picture the system in my head that really is a lot of friction on the orthogonal walls that is just being neglected (i.e. treated like frictionless surfaces when they are anything but). It would probably be prudent to only consider half of the wall lengths as friction resistance to account for possible soil disruption near the excavation side of the tank if I were to go this route, however.
Thanks for the insights!
RE: Rectangular Concrete Tank: Stability Forces
RE: Rectangular Concrete Tank: Stability Forces
Maine Professional and Structural Engineer
American Concrete Industries
www.americanconcrete.com
RE: Rectangular Concrete Tank: Stability Forces
www.PeirceEngineering.com
RE: Rectangular Concrete Tank: Stability Forces
Duplicate threads are sometimes frowned upon on Eng-Tips.
BA
RE: Rectangular Concrete Tank: Stability Forces