Time between excavating and concreting a bored pile

[geo321]

Good day,

2 questions please :
what is the maximum time allowed between excavating and concreting a bored pile without affecting pile integrity ?Is 24 hours ok ? I couldnt find anything in the specs.
2- if a bored pile is concreted, can we begin directly excavating the adjacent pile which is 3x diameter far ?
Thank yiu

 

[jayrod12]

Our general notes say that holes must be filled the same day they are drilled and that no more than 3 holes can be open at one time. So basically they should get a 3 hole headstart in drilling when you start to fill the first hole, and stop drilling when there is only time to fill the remaining holes.

But that's just our office notes (and come to think of it, my previous office as well). I do not know where these rules came from.

 

[hokie66]

Common sense, I think, jayrod. That has always been my stance as well. As to the second question by the OP, wait until after the first pile is filled. Would depend on the soil type, but it is not worth the risk.

 

[geo321]

Ok thank u jayrod12 and hokie66

 

[jayrod12]

Actually I missed an important point, our notes also include that you should not have to directly adjacent pile holes open at one time. So as hokie said, don't drill two adjacent piles, fill the first one. If you desire to leave a few (one or two) open while you are filling one then you should drill every other pile and then come back and infill the gaps.

 

[geo321]

Another thing por favor.

A working pile load test is required for a pile under the abutment. 2 piles are casted and one of these piles will be subject to the test.
4 anchor piles will be drilled, one of these piles will be really close to the second pile which will not be subject to the test. The second pile has been casted today and the contractor is asking if he cam drill tomorrow the anchor pile (which will be very near). Is this ok ? I dont have the minimum diatance of 3 diametera since the anchor pile wont be used in the working conditions of the bridge and i dont know if drilling after 24 hours may affect the concrete section of the pile poured one day ago.
thanks a lot