Crosshole Sonic Logging Tubes
Crosshole Sonic Logging Tubes
(OP)
I am working on a project that is including a deep foundation of drilled caissons. The geotechnical engineer has included a recommendation for cross hole sonic logging tubes to allow for possible non-destructive testing. The only additional information within the report specifies for (4) access pipes within the concrete.
I understand the tubes will be tied to the caisson rebar inside of the cage for the full length of the shaft. The typical diameter is usually 2" (inside). These can be either steel or PVC, and steel is usually recommended for better bonding. The end caps and couplers need to be watertight. The bonding between the concrete and the tube is extremely important.
Has anyone ever used these before and could give any additional insight and/or recommendations?
Thank you.
I understand the tubes will be tied to the caisson rebar inside of the cage for the full length of the shaft. The typical diameter is usually 2" (inside). These can be either steel or PVC, and steel is usually recommended for better bonding. The end caps and couplers need to be watertight. The bonding between the concrete and the tube is extremely important.
Has anyone ever used these before and could give any additional insight and/or recommendations?
Thank you.






RE: Crosshole Sonic Logging Tubes
http://www.olsoninstruments.com/
Note...I'm not affiliated in any way with Olson Instruments nor am I recommending its products...just check them for info.
RE: Crosshole Sonic Logging Tubes
I've seen so many CSL reports I'd bust if I read another one!
I will say this, who ever is doing the concrete operations better make sure the drilled shaft is clean, especially at the bottom and that if using a tremie method due to high water table, the seal best be watched closely. We've rejected several shafts on the basis of poor quality concrete at the bottom of the hole, likely due to poor cleaning and also due to poor seal in tremie operations.
One of the biggest problems especially on small diameter shafts is getting the contractor to drill a straight hole down the center of the shaft to pressure grout. This always brings up the question of what to do if the shaft can't be grouted....which the contractor never likes the answer.... And nobody ever likes to go around with the contractor.
Regards,
![[pipe] pipe](https://www.tipmaster.com/images/pipe.gif)
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RE: Crosshole Sonic Logging Tubes
Crushed PVC tubes (for sonic logging or shaft grouting) are not uncommon.