I have typically seen compaction testing required every 2,500 sq. ft for structural fill. Is there any published guidelines for specifying testing frequency?
1 test per 2500 square feet is referenced in the Florida Building Code and perhaps others, since it is based on the IBC. That is reasonable; however, additional specifications should be provided such as one density test per 50 linear feet of footing, and a minimum of 3 tests in any area per lift.
This is from Day's Foundation Engineering Handbook but is based on NAVFAC DM-7.2. It is based on volume rather than area. In order to get the frequency per area, I consider the lift thickness which will result in less frequency than Ron's input. However, Ron's input is reasonable to me and also supported by the IBC.
it really depends on what you are constructing and who is paying for it. for highways, dams, levees, or other heavy construction, all may be different than recommended above (Okiryu's reference touches on this). additional/minimum testing is required per day, per shift, per lift, per material change, when high or low values of density or MC pop up, or as the engineer sees fit, etc.
