<p><p><strong>References:<br></strong><em> Schaefer et al. (2016)<br>Mitchell (1981)<br>SHRP 2-Phase I Technology Assessment (2008)</em></p><p><strong>Method Summary</strong></p><p>The backfill gradation can be verified using a grain size analysis in the lab and using the resulting grain sizes to determine its suitability number (S_N). The grain size analysis should be performed in accordance with ASTM standards.</p><p><strong>Accuracy and Precision</strong></p><p>The test is only as accurate as the representative sample. Reliable values are obtained which can be used to assess the quality of the vibrocompaction fill material.</p><p><strong>Adequacy of Coverage</strong></p><p>One or several representative tests are usually performed based on the amount of backfill material being used.</p><p><strong>Implementation Requirements </strong></p><p>Performing a backfill gradation assessment is a simple method with little experience required.</p><p><strong>General Comments</strong></p><p>Verifying the backfill gradation before using it for a vibrocompaction process is important. This will provide an indication of the amount of compaction which can be achieved using the material. The lower the suitability number, the higher the degree of compaction can be achieved. This will help to increase the bearing capacity and liquefaction resistance and reduce settlement.</p></p>