Section 27-698. Where more than one pile type, pile capacity, or method of pile installation is used

Wherever it is proposed to: (1)  construct  a  foundation  for  a  building  utilizing  piles  of more than one type or
  capacity; (2) modify an existing foundation by the addition of piles  of
  a  type  or  capacity  other  than  those  of  the  existing piling; (3)
  construct or modify a foundation utilizing  different  methods  or  more
  than  one method of installation, or using different types or capacities
  of equipment  (such  as  different  types  of  hammers  having  markedly
  different  striking  energies  or  speeds);  or  (4)  support  part of a
  building on piles and  part  on  footings,  the  several  parts  of  the
  building  supported  on  the  different  types,  capacities, or modes of
  piling shall be separated by suitable joints providing for  differential
  movement,  or  a  report shall be submitted by the architect or engineer
  establishing to the satisfaction of the commissioner that  the  proposed
  construction  is  adequate  and  safe,  and  showing  that  the probable
  settlements and differential settlements to be expected will not  result
  in instability of the building or stresses in the structure in excess of
  the  allowable values established in subchapter ten of this chapter. The
  provisions of subdivision (d) of section 27-700 of article eight of this
  subchapter relating to required load tests shall  apply  separately  and
  distinctly  to  each  different  type  or  capacity of piling, method of
  installation, or type  or  capacity  of  equipment  used,  except  where
  analysis of the probable, comparative behavior of the different types or
  capacities  of  the  piles or the methods of installation indicates that
  data on one type or capacity of pile permits a reliable extrapolation of
  the probable behavior of the piles of other types and capacities.