tremie seal concrete slab design
tremie seal concrete slab design
(OP)
My question has to do with sheet pile cofferdams that are constructed in areas of high water table. Dewatering of the site is not allowed, so a tremie seal concrete slab will be placed at the bottom of the excavation. When designing the tremie seal slab, does the weight of the slab need to completely resist the hydrostatic pressure, or is a bond between the sheet piles and the concrete included. If a bond is used is it something like 5 psi, and then do you check theslab as an unreinforced slab. Is there any documentation, standards, or manuals that would outline the specific design of tremie seal slabs required thickness. These cofferdams are not for footing where concrete piles are present in the interior of the pit.





RE: tremie seal concrete slab design
RE: tremie seal concrete slab design
RE: tremie seal concrete slab design
http://www.pdhcenter.com/courses/g113/g113.htm
www.SlideRuleEra.net![[idea] idea](https://www.tipmaster.com/images/idea.gif)
RE: tremie seal concrete slab design
Could you post this to your website as itappers acess is limited, but the paper sounds very useful. Thanks
RE: tremie seal concrete slab design
RE: tremie seal concrete slab design
Example:
Pit is 17'x25'
Water table at a depth of 8'.
Top of tremie seal slab at a depth of 27'.
They come up with a 7' foot thick tremie seal slab.
How exactly does that cals?
RE: tremie seal concrete slab design
This is much thicker than 7'. Also, if the tremie is much thicker than 7', then the cofferdam will need to be much deeper with extra row(s) of bracing and more excavation.
Frequently, you can increase the sheet pile embedment below planned subgrade enough so that you can dewater without the bottom of the excavation heaving or piping (turning into a quick condition). Then, you won't need a tremie seal and you will need less excavation and bracing. I always try that before adding a tremie seal, especially if the new foundation need bearing piles.
RE: tremie seal concrete slab design
62 x 19 = 1,178 psf net pressure
1,178 / 150 = 7.8 ft concrete round to 7 feet.
I have seen similar calculations. Not correct, but probably how it was done.
RE: tremie seal concrete slab design
RE: tremie seal concrete slab design
RE: tremie seal concrete slab design
I am not feeling comfortable assuming some type of friction or bond between the sheet piles and the concrete without some widely accepted documentation or design procedures. I can't find any. I also don't want to be overly conservative with my designs. Any further discussion of this topic would be greatly appreciated.
Thanks.
RE: tremie seal concrete slab design