At-rest soil loads on a cantilever retaining wall?
At-rest soil loads on a cantilever retaining wall?
(OP)
I am designing an exterior wall of a water treatment plant. The plant floor will be higher than exterior grade (backfilled side is the interior). The liquid-supporting slab-on-grade floor slab will be placed roughly 18 ft. above exterior grade. The design will have to be a multi-step design:
1. Cantilever condition during construction and backfill
2. Restrained condition once the floor slab has set
The geotechnical report I'm reading recommends designing the cantilever wall for at-rest pressures. These are 60% higher than the active pressures I would usually use for a cantilever condition so my wall thickness, footing thickness, footing size, reinforcement, etc. are all much higher than expected. I want to get some other's input before contacting the geotechnical engineer. Do you agree with designing an 18 ft cantilever retaining wall for at-rest pressures? At that height I would expect the wall to tilt some creating an active condition.
1. Cantilever condition during construction and backfill
2. Restrained condition once the floor slab has set
The geotechnical report I'm reading recommends designing the cantilever wall for at-rest pressures. These are 60% higher than the active pressures I would usually use for a cantilever condition so my wall thickness, footing thickness, footing size, reinforcement, etc. are all much higher than expected. I want to get some other's input before contacting the geotechnical engineer. Do you agree with designing an 18 ft cantilever retaining wall for at-rest pressures? At that height I would expect the wall to tilt some creating an active condition.






RE: At-rest soil loads on a cantilever retaining wall?
RE: At-rest soil loads on a cantilever retaining wall?
RE: At-rest soil loads on a cantilever retaining wall?
I'd just prefer to design it conservatively once for its permanent loads, rather than having it switch from a cantilever analysis to a propped cantilever analysis.
RE: At-rest soil loads on a cantilever retaining wall?
But if he says it, you know its right.
RE: At-rest soil loads on a cantilever retaining wall?
RE: At-rest soil loads on a cantilever retaining wall?
RE: At-rest soil loads on a cantilever retaining wall?
I'm leaning towards bracing the wall which will allow me to more efficiently place my steel in the wall for both the construction and final conditions which will be similar. It would be nice for the opposing walls to brace eachother but I think that would interfere with the backfille operation.
I also thought about not backfilling the volume and using a framed slab at the 18' elevation but the owner doesn't want a vacant space in his building. Maybe I'll run a cost comparison. If the framed slab option is cheaper it may sway him.
RE: At-rest soil loads on a cantilever retaining wall?
RE: At-rest soil loads on a cantilever retaining wall?
EIT
www.HowToEngineer.com
RE: At-rest soil loads on a cantilever retaining wall?