Refusal to perform dynamic penetrometer tests

What does waste represent in dynamic penetrometer tests?

The limit of strokes that defines waste is variable from instrument to instrument. Strictly speaking, it is the number of shots that, corrected by the coeff. theoretical energy, does not exceed the maximum value of n ° hits of SPT about 90.

Beyond which it would be impossible to obtain the geotechnical parameters. Eg for a DM30 117 rounds (90 / 0.766), for DPDH 77 (90 / 1.165). All to say that the bench you are going through has a friction angle greater than 45 °