Capacity of Old Timber Piles
Capacity of Old Timber Piles
(OP)
Renovations of a c. 1926 Fire Station are planned. The building has a basement and is supported on timber piles with concrete pile caps. Groundwater is near the top of pile caps. The planned renovation will increase loads on the existing piles. Any non-destructive testing that can be used to estimate the capacity of the existing piles?





RE: Capacity of Old Timber Piles
Well, the piles should be in a generally good condition, owing to the moisure in the soil. Unfortunately, other than back-calculating the design capacity from construction records using modern design relations, I can't think of much that could be done to test the "actual" capacity of the piles. You may wish to play it safe and specify additional elements to take the change in load. I would try to justify the re-use/continued use of the existing piles, if at all possible.
Try contacting the Timber Pile Council. Maybe they have some ideas.
Jeff
RE: Capacity of Old Timber Piles
RE: Capacity of Old Timber Piles
RE: Capacity of Old Timber Piles
RE: Capacity of Old Timber Piles
Although we did not have a problem here, Big H is right, if you are working with piles at or near the water table, be sure they don't dry out.
RE: Capacity of Old Timber Piles
Now that you have determined the soil profile and strength properties via SPT and/or strength testing on collected specimens, perform a statice analysis (I use Allpile by Civilsoft). Use an appropriate factor of safety.
Also, I have performed a static load test by jacking between an old timber pile and a pile cap.