<p><p><strong>References:<br></strong><em>Avalle (2007b)<br>Avalle and Grounds (2004)<br>Bouazza and Avalle (2006a,b)<br>Scott and Suto (2007)</em></p><p><strong>Method Summary</strong></p><p>Geophysical/seismic methods include surface wave testing, cross-hole seismic cones, Ground Penetrating Radar (GPR), and resistivity. Use of surface wave and cross-hole seismic cone testing to assess compaction improvement under IR is described in the references listed above. These methods provide quantitative information of the strength and stiffness of the subsurface layers using shear wave velocity data with depth. Use of GPR or resistivity methods on IR projects is not documented in the literature.</p><p><em> </em><strong>Accuracy and Precision</strong></p><p>Accuracy and precision of these methods have not been documented in the literature.</p><p><em> </em><strong>Adequacy of Coverage</strong></p><p>GPR can provide better coverage spatially and vertically compared to other conventional seismic methods such as cross-hole logging, seismic cones, Multichannel Analysis of Surface Waves (MASW), etc.</p><p><strong>Implementation Requirements </strong></p><p>Special equipment and setup, and trained personnel are necessary to conduct the tests and analyze the results.</p><p><strong>General Comments</strong></p><p>These test methods can be used for QC and QA.</p></p>