Everynameistaken
Structural
- Jun 29, 2014
- 68
Hello All,
I have a question regarding the lateral loading condition on a buried structure that is below the water table.
The static condition is quite simple, At-Rest buoyant soil plus hydrostatic. However, when we need to consider seismic things get quite a bit more complicated. I have done quite a bit of reading and there appears to be little research and many differing opinions on how to consider things:
1. If we have with Conditions relatively dense materials say less than 10^-4 m/s permeability:
1A - Consider the M-O for yielding or Wood for non-yielding, use the FULL density of soil including the water. Then do we need to add the hydro static water load as well some say yes some say no?
1B - Consider the M-O or Wood equation using the buoyant density of soil then add the hydrostatic load, no consideration of any hydrodynamic.
2. If we have Conditions relatively "un-dense" materials say greater 10^-4 m/s permeability:
2A - Loose granular soils to boulders or 1 foot rip rap - Consider the M-O or Wood equation with buoyant density then either:
i) add hydro dynamic based on Westerguard and add hydrostatic
ii) add hydro dynamic based on Westerguard and do not add hydrostatic
i) do not add hydro dynamic based on Westerguard but add hydrostatic
2B - Loose granular soils to uncompacted boulders or 1 foot rip rap - Consider the M-O or Wood equation with FULL density then add hydrostatic or not?
There were some other articles that had a very complicated method for considering the amount of hydrodynamic to consider based on varying degrees of permeability!
Im sure there are many other combinations so I am looking for some Geotech input on what people recommend using.
Thanks
I have a question regarding the lateral loading condition on a buried structure that is below the water table.
The static condition is quite simple, At-Rest buoyant soil plus hydrostatic. However, when we need to consider seismic things get quite a bit more complicated. I have done quite a bit of reading and there appears to be little research and many differing opinions on how to consider things:
1. If we have with Conditions relatively dense materials say less than 10^-4 m/s permeability:
1A - Consider the M-O for yielding or Wood for non-yielding, use the FULL density of soil including the water. Then do we need to add the hydro static water load as well some say yes some say no?
1B - Consider the M-O or Wood equation using the buoyant density of soil then add the hydrostatic load, no consideration of any hydrodynamic.
2. If we have Conditions relatively "un-dense" materials say greater 10^-4 m/s permeability:
2A - Loose granular soils to boulders or 1 foot rip rap - Consider the M-O or Wood equation with buoyant density then either:
i) add hydro dynamic based on Westerguard and add hydrostatic
ii) add hydro dynamic based on Westerguard and do not add hydrostatic
i) do not add hydro dynamic based on Westerguard but add hydrostatic
2B - Loose granular soils to uncompacted boulders or 1 foot rip rap - Consider the M-O or Wood equation with FULL density then add hydrostatic or not?
There were some other articles that had a very complicated method for considering the amount of hydrodynamic to consider based on varying degrees of permeability!
Im sure there are many other combinations so I am looking for some Geotech input on what people recommend using.
Thanks