<p><p><strong>References:<br></strong><em>Braithwaite and du Preez (1997)<br>Building Research Establishment (2003)<br>Kristiansen and Davies (2003)<br>Kristiansen and Davies (2004)<br>SAICE (2006)<br>Serridge and Synac (2006)<br>Simpson et al. (2008)</em></p><p><strong>Method Summary</strong></p><p>This method tests the improvement resulting from RIC by using in-situ penetration test results, from SPT, CPT, Becker Penetration Test (BPT) or Dynamic Probe (DP) tests. In-situ penetration tests can serve as either quality control or quality assurance. Quality control testing during treatment often involves in-situ penetration tests which may form part of the final assurance testing regime.</p><p>Post-compaction tests such as SPTs and/or DP tests are performed and compared to the pre‑compaction test results. These pre- and post-compaction results illustrate the increased bearing capacity of the material and are expressed in N-values (SAICE 2006). In-situ penetration tests may be used where changes in properties of soil due to dynamic compaction can be measured and directly related to criteria set out in the contract documents or compared with pre‑treatment test data (Building Research Establishment 2003). Due to the speed of testing, continuous DP tests are ideal for use before, during, and after compaction in order to demonstrate the effectiveness and depth of treatment (Braithwaite and du Preez 1997). In Canada, BPTs have been used for coarser soils (Serridge and Synac 2006).</p><p><strong>Accuracy and Precision</strong></p><p>In-situ tests are not always accurate but are useful for evaluating improvement based on pre- and post-compaction test results. Typically, it is beneficial to carry out in-situ penetration tests to confirm ground improvement at least two weeks after compaction, due to an observed increase in density as a result of aging effects (Kristiansen and Davies 2003). It may be difficult to evaluate the soil improvement accurately in sites with heterogeneous fills (Serridge and Synac 2006).</p><p><strong>Adequacy of Coverage</strong></p><p>Sufficient coverage requires many penetration tests. Frequency of testing is affected by factors particular to each project such as the variability of the ground before treatment and the nature of the structure to be supported and its sensitivity to post-treatment movements (Building Research Establishment 2003).</p><p><strong>Implementation Requirements </strong></p><p>Experience and equipment necessary to perform in-situ penetration testing are commonly available.</p><p><strong>General Comments </strong></p><p>Correlations can be used to relate blow count or penetration resistance to liquefaction susceptibility or bearing strength.</p></p>