Hydrostatic pressures/vacuum evidence

[Bill338]

One of my charges has developed problems which I firmly believe is caused by hydrostatic pressures(and resultant sedimentary vacuum)brought on by tidal pressures. I have a 200K gallon pool surrounded by roughly 28K sq.ft. of deck area. The location of this "problem" is approximately 200 feet in from average high tide, with seasonal distances falling to less than 100 feet. Average depth of pool is 3.5ft. Over the last 12 months simple "in pool" fractures have now become compound fractures and over the last 3 months shear fractures have appeared at the coping and at the radius of the base and walls. The deck has increasingly developed stress cracks with the cool deck popping off. I have done acoustic soundings and find large voids under the deck area which are relative in position to fractures in or around the pool. Is it possible to pump a specific compound under the deck to solidify the sand substrate and then fill the voids with wet mix or possibly a urethane foam? Compaction reports? Don't ask, I inherited this nightmare. Tear-out is no option. This project sets in the middle of a flood plain (Atlantic, Myrtle Beach). I'd be glad to email more specifics.

 

[Focht3]

This is a bit late, but here goes.

I don't think the tides have much to do with the problem - you are dealing with a poorly constructed project. Pumping "pooky" into the voids is a temporary fix; the only good repair is R&R. Since the pool shell is cracked, rebar corrosion is a big concern.

Yank it out and start over.



Please see FAQ731-376 for great suggestions on how to make the best use of Eng-Tips Fora. See faq158-922 for recommendations regarding the question, "How Do You Evaluate Fill Settlement Beneath Structures?"