OWNER:
Atlantic Land Corporation
660 Dunlap Drive
Mobile, Alabama 36652
PROJECT
ENGINEER:
Southern Earth Sciences, Inc.
P.O. Box 160745
Mobile, Alabama 36616
DESIGN/CONSTRUCT
CONTRACTOR:
Synergy Earth Systems, Inc.
26240 Equity Drive
Daphne, Alabama 36526
The Atlantic Land
Corporation, a subsidiary of Atlantic Marine, operates and maintains
a dredge disposal impoundment on their property in Mobile, Alabama.
The facility, which borders Mobile Bay, was initially constructed 1954.
In 1998, the outboard slope of a section of the containment dike experienced
some instability. The slide was the result of erosion of the outboard
dike toe by wave action. Atlantic Land Corporation had scheduled a dredging
operation and needed to repair the dike prior to beginning. Synergy
Earth Systems, Inc. (SES) was retained to design and construct the repair.
Design calculations
indicated that, to permanently repair the dike, reconstruction of the
dike toe would be required. However, this would require a Corps of Engineers
permit that could not be obtained in time to perform the scheduled dredging
operation. Therefore, a temporary repair was designed to allow the dredging
operation to take place while a permit was being obtained for the long-term
solution. The temporary repair consisted of reconstructing an approximate
270-foot reach of the dike using geogrid soil reinforcement and geosynthetic
strip drains to control seepage. About one week after construction of
the temporary repair, Hurricane Georges hit the Gulf Coast and caused
major erosion damage to the containment dikes. With the dredging contractor
on stand-by, an emergency dike repair was designed and constructed.
The selected alternative
was to set the existing dike back from the damaged area. However, this
required that the dike be constructed partially over soft dredge spoil
material. Geogrid reinforcement was utilized to maintain stability of
the relocated dike. Approximately 1100 feet of dike was realigned in
three days. Portions of the construction work were performed concurrently
with the dredging operation underway resulting in minimal stand-by time.
