Griffin Dewatering was hired to provide a workable dewatering plan to facilitate the“facelift” of a swanky mall in Palm Beach — all while maintaining a low profile to accommodate everyday mall business.
When the Palm Beach, Fla., area was growing into the north end of the county, it became apparent that a new shopping venue was required. After all, these residents wouldn’t want to travel all the way to the Island of Palm Beach to shop at Sak’s Fifth Avenue or Nordstrom.
Pepper-Southern General Contractors of Atlanta was hired by the owner (Forbes-Cohen Florida Properties) in 1988 to construct the new project, calling in Griffin Dewatering to provide the proper methods and materials to be utilized when dewatering the proposed structure’s footings.
The proposed footings were designed to support both floor slabs and structural columns, as well as the new glass enclosed central elevator and adjacent water features and fountains. The work was successfully concluded in 1999 and the mall opened with great success. But now 19 years later, some of the shine is gone, the tile grout is stained, the elevator is old and it’s time to give the mall a facelift. Flash forward to 2007, when the Ft. Lauderdale, Fla., office of Whiting-Turner General Contractors hired Griffin Dewatering of South Florida to provide a workable dewatering plan to facilitate the demolition of old, construction of new and maintain a “low profile” to accommodate everyday mall business. Griffin commenced its portion of the project in April.
Griffin’s contract for services included dewatering of excavated areas where the new Grande Fountain, its control vault and the new elevator are to be constructed. The problems that Griffin had to solve were essentially three-fold. First it had to provide an appropriate dewatering plan to facilitate excavation and placement of underground plumbing lines, concrete structures and fountain/pool shell.
In addition, the dewatering process had to be environmentally compatible so as not to disturb daily business of the neighboring stores and eateries. As part of its dewatering plan, it also had to face challenges involving limited availability of a disposal location for dewatering effluent, in addition to working only at night and after hours.
The solution was to first install a perimeter wellpoint/wick point system with one 12 in. x 15 ft long (or approximately 7 ft below excavation bottoms) screened and wicked wellpoints at 48 in. +/- centers/horizontally. This procedure minimized or eliminated soil movement from adjacent existing footings and slabs by reducing hydrostatic groundwater pressure to a point well below the excavated areas.
The dewatering pump was electrically powered and placed in an enclosed box, thus noise level was well below any audible level in the work area. A typical wellpoint pump’s vacuum system is mineral oil lubricated and sealed thereby emitting hydrocarbon vapor during the cooling and sealing process.
In this case, Griffin South Florida called upon Griffin Southwest & Griffin Pump & Equipment for an appropriate size of electrically powered wellpoint pump with a water cooled/sealed vacuum pump. It just so happened that a newly refurbished Griffin model 4NCRE with a Travini vacuum pump was available and suited this project perfectly.
The size was right to be placed inside the mall (transported through service corridors), the motor size worked with the available three phase power and the general contractor installed a flexible steel exhaust line to the adjacent ceiling fans to vent any water vapor or groundwater odor.