<p><p><strong>Reference(s):</strong></p><p><em>Dumas and Beaton (1992)</em><em>Miller et al. (2004)</em><em>Schaefer et al. (1997)</em></p><p><strong>Method Summary<br></strong>Dilatometer tests can be useful when the objective of DDC is to increase bearing capacity or reduce settlement, since they provide direct correlations to the applicable soil parameters. Dilatometer tests should be performed both before and after the deep dynamic compaction program so that the results can be compared and the improvement in properties determined.</p><p><strong>Accuracy and Precision<br></strong>DMTs provide a good estimate of the lateral pressure and stiffness at different depths.</p><p><strong>Adequacy of Coverage<br></strong>Like CPTs and SPTs, dilatometer tests can be used to get an accurate picture of the subsurface profile. However, DMTs are slower and more expensive than SPTs and CPTs, and fewer correlations with soil properties are available.</p><p><strong>Implementation Requirements<br></strong>Dilatometers are relatively easy to perform and produce no spoils. DMTs can be difficult to impossible in gravels or soils with large debris.</p><p><strong>General Comments<br></strong>Dilatometers can be used in any deep dynamic compaction program and are especially useful in determining whether adequate bearing capacities have been achieved or if potential settlements have been reduced. Dilatometers can also be used in layered soils where the different layers may have different levels of improvement after completion of the deep dynamic compaction program.</p></p>