Build Pile Cap In High water area, under Active Airport terminal 3

[dragondipaula]

Does anyone have a way of stopping water intrusion into a pile cap while I excavate, chip piles down, set the rebar mats, and then place concrete in a pile cap. Other than well point. Multiple pile caps but, the largest is about 15'x13'. Here are the tricky parts.
1. Under an active airport terminal, with the closest daylight area about 500' away.
2. Soil is contaminated and thus the water smells like old jet fuel.
3. Encounter ground water at approximatly 2' into the excavation, going 4' deep.

 

[BigH]

Why not ground freeze? Just an alternative to grout. Another possibility - thinking out of the box - can you not excavate - or drive wood slats then excavate out, put in a "steel plate" (to act as your pile cap reinforcement across the tops of the piles which I hope do not extend to the ground surface (with a hole for grouting and grout tube) - tremie in the concrete above the steel plate. Then pressure grout beneath the steel plate. Just a thought. Alternatively, you could sink a well foundation, put in a concrete plug to act against uplift, then clean out and work in the dry for the pile cap and elevator pit.

 

[dragondipaula]

One word boys, Miami!