Section 27-692. Minimum spacing of piles

Piles shall be spaced to meet the
  following requirements:
    (1) Spacing of piles shall provide for adequate  distribution  of  the
  load  on  the  pile group to the supporting soil, in accordance with the
  provisions of subdivision (b) of section 27-700 of article eight of this
  subchapter.
    (2) In no case shall the minimum center-to-center spacing of piles  be
  less  than  twenty-four  inches,  nor  less than the values for specific
  types of piling as indicated in article ten of this  subchapter.  Unless
  special   measures  are  taken  to  assure  that  piles  will  penetrate
  sufficiently to meet the requirements of section 27-689 of this  article
  without  interfering  with  or  intersecting  each  other,  the  minimum
  center-to-center spacing of piles shall be twice the average diameter of
  the butt for round piles; one and three-quarters times the diagonal  for
  rectangular  piles;  or,  for taper piles, twice the diameter at a level
  two-thirds of the pile length measured up from  the  tip.  In  cases  of
  practical difficulty, the spacing of new piles from existing piles under
  an adjacent building may be less than the above values provided that the
  requirements  relating  to  minimum  embedment and pile interference are
  satisfied and that the soil under the proposed and existing buildings is
  not overloaded by the closer pile grouping.