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Concrete Problems

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I have an interesting problem I need some assistance with.  The background
data goes something like this:

The project is a multistory hotel with block and plank construction.  The
soils dictated the need for drilled pier support with structurally suspended
(void box construction) grade beams.  Wind speed 70mph, zone 0.  The piers
are currently in place as well as the grade beams.

Prior to pouring the grade beams, the testing agency made an inspection of
the project and noted "mud" on top of the piers.  The inspector then had to
go "down the hill" to inspect some steel in a detention pond prior to
concrete placement.  By the time he made it back "up the hill," the
contractor had already placed concrete on the piers, without a second
inspection.

The Owner/contractor (as expected) indicated that all of the piers had been
cleaned prior to concrete placement.  They said they had an affidavit from
the individual who did the work.  I told them to send me the affidavit
(notarized) and by the way, go ahead and dig up two piers and let the
inspector check them.  After excavation and power washing, both of the piers
had conical voids of varying size, between the piers and the grade beams.  I
selected another 10 or 15 piers to excavate, clean, and inspect.  The
majority of these piers also had conical shaped voids of varying size.  In
several locations, I could see (from pictures provided by Owner/contractor)
the vertical rebar in the piers as well as some of the pier stirrups.

The Owner called and asked, "What do you think?"  I told him he better go
ahead and excavate all of the pier/grade beam intersections, clean them, and
have them photographed and inspected.

My dilemma now is how do I fix this problem.  My thoughts are to excavate
below the grade beam, support the beams if necessary, and demo about 12 or
24 inches of the pier, clean the rebar, split a sonotube and reform the
pier, and pour back with a flowable high strength concrete.  Am I missing
anything?

Brian K. Smith, P.E.