The scope of work indicates a 5” slab with 8 helical piles (I presume equally spaced in a manner as shown below in the concept)….there are 2 ways to interpret this proposed design.
- the slab is meant to span to the 8 helical piles like a “2-way” spanning slab (such as in a building) in the event that the soil subsides below it (which is extremely improbable given the compaction that will occur) or soil expansion/heaving lifting the slab. If this interpretation is correct, the 5” is not thick enough and will fail in flexure at mid span and punching shear at the supports.
- the slab is not meant to span to the 8 helical piles and is meant to sit directly on the imported base without the consideration for heaving or subsidence of the soil. If this interpretation is correct, there is no purpose of the 8 helical piles as the slab is being supported uniformly by the soil without the piles.
SCOPE OF WORK:
- SITE PREP
- Removal of obstructions/railings/ salad bar
- Electrical safe off
- Zip wall installation, build pony wall to accommodate 12 foot ceilings
- Security/safety fencing
- Traffic safety cones
- Ramp construction
- Construct 8ft. wide ramp from sidewalk grade to construction site grade. (Necessary for stair access).
- DEMOLITION
- Saw cutting
- Concrete removal
- Haul-off
- Requires qty-2, 10 cyd. Lowboy roll-off bins.
- EXCAVATION
- Excavate site to 24in below existing slab grade.
- Excavation will be done with diesel powered mini excavator, and mini loader.
80 cyds. Removal and dump fees included. Hauling/transport
- Dirt hauling provided by Golden Seven Trucking, Inc.
- SOIL STABILIZATION
- HMI 402 deep soil injection
- Inject HMI 402 to a depth of 8 ft. at 2 ft. spacing to stabilize and pressure compact soil.
- COMPACTION
- Initial compaction of in-place soil[s]
- Compact existing soil after soil stabilization.
- BACK-FILL
- Road base/import
- Install 80 cyds. of road-base
Compaction of road base
- Compact at 6in. lifts to 94
- INSTALL QTY-(8) HELICAL PIERS
- Install ECP Model 288 helical piers at 8 locations to a depth of 20feet.
- REBAR/VAPOR BARRIER INSTALLATION
- Drill and dowel installation
- Drill existing slab perimeter at 2ft. intervals.
- Install #4 rebar dowels with epoxy.
- Requires Deputy Inspection.
Install 10 mil vapor barrier. Install #4 rebar at 2ft. intervals.
- Tie all intersections.
- CONCRETE
- Install 2500 psi concrete at a thickness of 5in, 41’x26’.
- Smooth finish to match existing.
- Requires pump truck
- 17cyds.
Thanks,
Jeremy Livermore, S.E., P.E.
Structural Engineer, License #: S5905
Civil Engineer, License #: C71491
OC Structure Check
1133 Camelback St.
Unit #11101
Newport Beach, CA 92658
949-478-4026 cell
www.ocstructurecheck.com
jeremy
