Section 27-691. Tolerance and modification of design due to field conditions

(a)  Tolerance in alignment of the pile axis. If the axis of any pile is
  installed out of plumb or deviates from the  specified  batter  by  more
  than  four  per  cent  of  the pile length, the design of the foundation
  shall be modified as may be necessary to resist the  resulting  vertical
  and lateral forces. In types of piles for which subsurface inspection is
  not possible, this determination shall be made on the exposed section of
  the  pile, which section, at the time of checking axial alignment, shall
  not be less than two feet. In piles  which  can  be  checked  for  axial
  alignment below the ground surface, the sweep of the pile axis shall not
  exceed four per cent of the embedded length.
    (b)  Tolerance  in  location  of  the head of the pile. A tolerance of
  three inches from the  designed  location  shall  be  permitted  in  the
  installation  of  each  pile,  without reduction in load capacity of the
  pile group.  Where piles are installed out of position in excess of this
  amount, the true loading on such piles shall be analytically  determined
  from  a survey which defines the actual location of the piles as driven,
  and using the actual eccentricity in the pile group with respect to  the
  line  of  action  of the applied load. If the total load on any pile, so
  determined, is in excess of one hundred ten per cent  of  the  allowable
  load bearing capacity, correction shall be made by installing additional
  piles  or  by  other methods of load distribution, as required to reduce
  the maximum pile load to one hundred ten per cent of the capacity.
    (c) Bent piles. Where piles have been bent  during  installation,  and
  the  amount of the bend exceeds the allowable tolerance for alignment of
  the pile axis in subdivision (a) of this section, the condition shall be
  investigated and, where required, correction made by the installation of
  additional piles, by strengthening  the  bent  piles,  by  reduction  in
  capacity or other means acceptable to the commissioner.