<p><p><strong>References:<br></strong><em>Schaefer et al. (2016).<br>Hussin (1994)<br>ISSMGE TC-17 Working Group D, Report D4<br>Mankbadi et al. (2004)<br>Mankbadi et al. (2008)<br>Schaefer et al. (1997)<br>Serridge and Synac (2007)</em></p><p><strong>Method Summary</strong></p><p>There is a limited availability of verified design methods used to predict the soil-column interaction parameters and settlement characteristics of VCCs. As a result, a primary QC/QA method utilized with VCCs is a load test program. Load testing has been documented in multiple formats, including standard axial compressive load tests, quick axial compressive load tests, dynamic load tests, and statnamic load tests. The load testing can be conducted on individual columns or on column groups. The results are used to verify the predicted settlement and bearing capacities as well as to establish the installation procedure to be used throughout the installation of the production VCCs.</p><p><strong>Accuracy and Precision</strong></p><p>Load testing helps set the procedures to be used during the installation of VCCs. If the methods used during the installation of the test VCCs are implemented during the installation of the production VCCs for a given site, the load test can reasonably predict the performance of the foundation system. When used in conjunction with proper monitoring of each VCC installed, the load testing procedures can provide proper construction methodology for the VCCs of a given project. It should be noted that in most case histories available, the chosen test method is conducted on individual columns rather than column groups, and therefore may not be completely reliable for predicting settlements of the overall system. However, load testing column groups can be very expensive and therefore, is not practical in some cases.</p><p><strong>Adequacy of Coverage</strong></p><p>As discussed in the <em>Accuracy and Precision</em> section, load testing should be conducted and used in conjunction with proper monitoring of each VCC installed. If similar construction methods are used for the test VCCs as are used for the production VCCs, the load tests can provide an adequate assessment of the production VCCs.</p><p><strong>Implementation Requirements </strong></p><p>Load testing is a very common practice. The time required can range from hours to days, depending on the method being implemented.</p><p><strong>General Comments </strong></p><p>Load testing is valid if the VCCs used in production are constructed using similar techniques as are used to construct the test column.</p></p>