Measurement of Soil Layer Strength With Plate Sinkage and Uniaxial Confined Methods

A method is presented for the calculation and verification of soil layer compaction strength values from in situplate sinkage data, as compared with traditional laboratory compression testing of confined soil cores. Experiments wereconducted in a prepared soil bin by compression loading with a portable soil plate penetrometer for the unconfined platesinkage tests and by confined uniaxial tests on soil cores. It was shown that soil compaction strength determined fromunconfined in situ plate sinkage tests was statistically similar, at the p = 0.05 level, to results from paired confined tests. Thisresult suggests that both methods can be applied interchangeably. Therefore, the relative ease of conducting in situ platesinkage tests may be an attractive alternative for field compaction studies.