For some time C.L. Benton &
Sons of Myrtle Beach have been using empty Monotubes as anchor piles at various sites on
static load tests. Some very high loads had been developed in tension on these Monotubes
without any evidence of pull-out no matter what type of pile was being tested in
compression. Normally, the same four anchor piles were being used, then vibrated out to be
reused for another test site in the future.
With codes requiring designers to include substantial uplift loads because of anticipated
high winds in the area, C.L. Benton & Sons became curious as to what it would actually
take to pull a Monotube. |
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At their expense and under supervision of
Allen Folline Associates and C.L. Crowther, Consulting Engineer, the driving and testing
to ASTM D-1143 specifications was carried out.
In Mr. Folline’s and Mr. Crowther’s report, their conclusion as to the results
of this excellent test was expressed as: "It is our opinion that the sand
densification from the "wedging" action of the driven pile tapered section, as
well as the ability of the pile tip to penetrate cemented layers, are the reasons for the
high uplift load resistance." It was further pointed out that substantial uplift
loads without unusually high driving energies can be developed with the relatively short
uniformly tapered Monotubes in the soils typical to this coastal area. |
