Subgrade Stabilization
Subgrade Stabilization
(OP)
In a 50 feet continuous footing, if we encountered with 12 feet length of sand fill (SW/SP) in the center of the subgrade, what would be your recommendation to stabilize the subgrade in this location.
The depth of the sand fill is not sure, but it is approximately around 10 feet deep.
Suggestions are greatly appreciated.
Thank you.
The depth of the sand fill is not sure, but it is approximately around 10 feet deep.
Suggestions are greatly appreciated.
Thank you.





RE: Subgrade Stabilization
RE: Subgrade Stabilization
Civilperson, I don't think jumping jack is good for compacting sand on a subgrade. And if he needs deep compacting, the vibrating plate would not do.
RE: Subgrade Stabilization
f-d
¡papá gordo ain't no madre flaca!
RE: Subgrade Stabilization
RE: Subgrade Stabilization
1. Engineered fill: dig it out and relay it with engineered fill (check with a geotech engr for local specs).
2. Extended footing: construct a steepsided trench down to contact competent native soil, fill up with flowable, lean mix concrete (unshrinkable fill) to the underside of the footing. Due to the different supporting characteristics undercross the footing, transitions in subgrade or structure strengthening should be provided in the footing unit.
3. Piers or short piles.
Again, as others indicated, if data shows the fill is engineered, you do not have to remove it, get a geotechnical firm assess the condition (compactness) and if it is considered competent, you may revise you footing design based on a different soil condition and just leave it there and build your foundation over it, provided that no utilities buried within it and surface improvement carried.
Anyway, a geotechnical engineer should be involved for the site condition.