Project Location: St. Louis, MO
Owner: Army Corp of Engineers, US Fish and Wildlife Service
GC: J. Gray Construction INC.
Project Revenue: $900,000.00
Project Start and End Date: 2007- 2008
SUMMARY
As part of the USACE environmental restoration initiative in this area, a cofferdam was to be constructed in the middle of the Mississippi River.
THE CHALLENGE
A water control structure needed to be built safely inside the limits of the earthen cofferdam that was constructed roughly 1,000 ft. from the riverbank. The USACE required a dewatering solution that established 16 ft. of drawdown below the excavation subgrade.
THE SOLUTION
The designed dewatering system included the installation of nine (9) deep wells on the outside edge of the earthen cofferdam. All wells were drilled to a depth of 80 ft. and pumped at rates between 1750 and 2100 GPM each. Additionally, Griffin installed two piezometers inside of the coffer-dammed area to verify system performance.
THE GRIFFIN DIFFERENCE
Griffin has expert knowledge of the aquifer characteristics along the river. The Griffin Field Crew successfully installed the dewatering system in challenging site conditions with very little drilling elevation head.