Allowable stresses for designing piles shall be as specified in Section 1809, 1810, and 1811. Allowable stresses greater than those specified for piers or for each pile type in Sections 1809 and 1810 are permitted where supporting data justifying such higher stresses are filed and approved by the commissioner. Such substantiating data shall include:
- A soils investigation in accordance with Section 1802.
- Pier or pile load tests in accordance with Section 1808.2.8.3, regardless of the load supported by the pier or pile. The design and installation of the pier or pile foundation shall be under the direct supervision of an engineer knowledgeable in the field of soil mechanics and pier or pile foundations who shall certify to the commissioner that the piers or piles as installed satisfy the design criteria.