Pile load test, ASTM vs BS
Pile load test, ASTM vs BS
(OP)
When we compare the requirements of compressive axial pile load test of BS standard and ASTM standard, it is observed that the requirements of ASTM are very strict when compared to the BS standard. For instance, ASTM requires that the clear distance between reaction pile and test pile should be a more than 5 times the pile diameter (test pile or reaction, whichever is greater), whereas the BS standard requires only 3 times pile diameter, that too centre to centre. So the difference is too much. Also, the ASTM required calibration of jacks and provision of load cells, and there is no such requirement in BS standard.
I think that the ASTM standard is too conservative. I also see that in US, mostly driven piles are constructed. So there are greater number of piles but less pile capacity. So it is easier to make a smaller platform for the test. Dynamic test is also carried out more frequently so the requirement of static is also reduced.
Please share your opinion.
I think that the ASTM standard is too conservative. I also see that in US, mostly driven piles are constructed. So there are greater number of piles but less pile capacity. So it is easier to make a smaller platform for the test. Dynamic test is also carried out more frequently so the requirement of static is also reduced.
Please share your opinion.





RE: Pile load test, ASTM vs BS
You can do something about that. Here is the procedure: "How ASTM Standards Are Developed - Modify Existing Documents"
BTY, I don't say this to be "funny" or sarcastic. I have submitted a detailed, documented proposal for a change to an AISC document. Nothing may happen, but I've tried.
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RE: Pile load test, ASTM vs BS
RE: Pile load test, ASTM vs BS
RE: Pile load test, ASTM vs BS
I'd say that you are lucky that no one checks the books. I have also conducted a number of load tests, i have even failed some of them and learned quite a few things from these experiences. Astonishingly, I did not omit anything from the book in these tests and still the load tests failed; actually the setup failed.
It is true that in the presence of a geotech expert, noone really questions validity of the setup.
We have to conduct a load test of 1500tons on a project but the consultant is very stubborn and is not willing to compromise the code. It took us around 3 months to actually make the setup as per the book. We will be starting soon.
RE: Pile load test, ASTM vs BS
RE: Pile load test, ASTM vs BS
RE: Pile load test, ASTM vs BS
RE: Pile load test, ASTM vs BS
Also, in case of a Kentledge system, it is very expensive to arrange long beams to built a platform for large diameter piles. And the influence of pad footings is not like that of reaction piles. The requirements should also be segregated based on the method used for the testing of the piles.
RE: Pile load test, ASTM vs BS
RE: Pile load test, ASTM vs BS
For friction piling, 3x spacing is often considered a reasonable minimum for a specified design load (P). Concept pressure distribution shown below:
Then, what spacing is reasonable for a friction pile load test at 200% of P? Concept pressure distribution:
A point-bearing load test concept pressure distribution looks reasonable, too:
A compromise answer may be > 3x, but could easily be < 5x.
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