Overloading existing piles
Overloading existing piles
(OP)
Hi, I have an existing building on piles which will be renovated and found that the piles will be overloaded about 10%~20% above the allowable pile capacity (ultimate capacity divided by a FOS of 3).
I saw also this:
http://www.eng-tips.com/viewthread.cfm?qid=220274
I understand that Chapter 34 of the IBC allows for 5% of overstress when evaluating existing structures, but is this related to the ultimate or allowable resistance/capacities. As you know, geotechnical stuff is still using ASD method so just want to hear what you think.
I saw also this:
http://www.eng-tips.com/viewthread.cfm?qid=220274
I understand that Chapter 34 of the IBC allows for 5% of overstress when evaluating existing structures, but is this related to the ultimate or allowable resistance/capacities. As you know, geotechnical stuff is still using ASD method so just want to hear what you think.





RE: Overloading existing piles
RE: Overloading existing piles
Point bearing or friction piling? (IMHO, point bearing often have a lot of reserve capacity.)
How much would the building's design live load rating have to be reduced to bring the pile loading down to allowable?
(Not a joke, we did something like this on one project.)
May have another suggestion, if the above don't work out.
www.SlideRuleEra.net
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RE: Overloading existing piles
The piles are end bearing in medium dense gravel. Friction contribution along the shaft is minimal. Ultimate capacities were calculated the upper bond of the available geotechnical parameters so it was not in the conservative side.
About reducing the loads, I will need to talk with the structural.
Appreciate the input !
RE: Overloading existing piles
www.SlideRuleEra.net
www.VacuumTubeEra.net
RE: Overloading existing piles
Also,what sort of tolerance can the building handle as to differential settlement? Perhaps in the remodeling the added load caused cracks won't show up after finishing the walls, etc.
One precaution might also be adopted. That is a detailed record of floor elevations now and later what the new situation is like. You may be surprised-to see no change or at least minimal, considering the end bearing situation for the piles.
RE: Overloading existing piles
Also, I noted that in the IBC 2015, Chapter 34 Existing structures was deleted...
RE: Overloading existing piles
RE: Overloading existing piles
Chapter 34 from the IBC has been replaced with the International Existing Building Code. Free online read only access to I-codes at https://codes.iccsafe.org/public/collections/I-Cod...
RE: Overloading existing piles
In my gut feeling with additional 20%load will give a FOS 2.5. In the existing building the piles had been no excess pore pressure anymore, it means the strength is higher (x%) than the strength during installment.
RE: Overloading existing piles
RE: Overloading existing piles
RE: Overloading existing piles