BEST DEWATERING METHOD IN FOUNDATION EXCAVATION 1

[redshot]

OUR CONSTRUCTION SITE IS ABOUT 300 M FROM SEA.AFTER SOIL INVESTIGATION, WE FOUND OUT THAT SUB-SURFACE MATERIAL IS CORRALINE SILT CLASSIFIED AS DENSE TO VERY DENSE. BUT TOO MUCH WATER IN THE AREA. WE TRIED OPEN SUMP PIT DEWATERING BUT THE AREA STILL WET. OUR WATERPROOFING STARTS AT PILE CAP UP TO THE RETAINING WALL.WHAT IS THE BEST DEWATERING METHOD FOR THIS SITE CONDITION?PLEASE IF ANY EXPERT CAN HELP ME..

 

[fattdad]

unless you are working for the contractor the typical specification makes construction dewatering the means and methods of the contractor. It's just not related to the betterment of the completed project.

f-d

¡papá gordo ain’t no madre flaca!

 

[redshot]

fattdad,
Im working for the contractor and we tried open sump with dicthes to dewater the area but still the method does not work effectively.

 

[cvg]

sheet piling might be necessary around the perimeter of the site. sumps do not work well to reduce the pressure on the walls of the excavation nor do they work well with fine grained material, well points or vacuum wells work better for this.

 

[BigHarvey]

a pumping test would be a good start to see if dewatering is possible without a watertight barrier around the excavation or not. Sheetpiles is a solution but can prove expensive ( possibility of hiring them ?, cost of removal = cost of installation roughly ). A thin grout slurry wall ( 50 mm thickness )might prove less expensive.

 

[dicksewerrat]

How deep is the soil layer you described? Can you put in what I would call 'wells' 20 feet deeper thatn you need? 12 inch or 16 inch well casings inside 16 or 20 inch drilled shafts and 4-6 inches of pea gravel to assist in the drainage to the wells. The first well would be where you did the pump test( suggested by BigHarvey) to see if the soil will give up enough water to help the situation.

Richard A. Cornelius, P.E.

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