Purpose: The purpose of this regulation is to establish the requirement for documenting, as part of the permanent project record, the as-constructed geotechnical and concrete materials aspects of all major, complex and unique engineered projects constructed by USACE. Major construction projects are those that fall in the category of multimillion dollar, multipurpose projects including all embankment and concrete dams and their appurtenant structures, and/or any structure for Civil Works projects involving more than 25,000 cubic yards of concrete. Unique and complex construction projects for both Military and civil works projects include those which, regardless of size or cost, which (a) had unusual or very stringent design requirements or performance criteria, (b) and/or encountered difficult or unusual foundation, concrete or other geotechnical challenges, or (c) for which unique or innovative design procedures, construction procedures or materials were utilized. It is further the intent of this regulation that existing project documentation be revised to include the as-constructed geotechnical and concrete aspects of all subsequent major modifications. In the absence of existing documentation, the project completion report for major modifications should be expanded to capture available information for both the original construction and the modification.