<p><p><strong>Reference(s):</strong></p><p><em>Hocking (2003)<br>Hocking and Hebner (2006)</em></p><p><strong>Method Summary</strong></p><p>Hocking (2003) developed an in-situ test device for determining soil liquefaction tendency and its prevention by electro-osmosis. This testing method is patented (US Patent No. 6,615,653 B1, Sep. 9, 2003). The use of this method has been demonstrated in some field studies (e.g., Hocking and Hebner 2006). The method involves using a driven or self-boring probe with a plurality of expanding and contracting bladders that imposes a cyclic shear stress reversal on the soil in-situ. Pore water pressures are monitored while applying cyclic shear stresses. A pore water pressure increase during cyclic shear stress reversals indicates a contractive soil with the potential to liquefy. The potential of electro-osmosis in preventing soil liquefaction is assessed by energizing a group of at least three electrodes by a DC power source during the potential onset of liquefaction, and measuring the reduction in pore water pressures during subsequent repeated shear stress reversals imposed on the soil by the device (Hocking 2003).</p><p><strong>Accuracy and Precision</strong></p><p>The accuracy and precision of the device is not known.</p><p><strong>Adequacy of Coverage</strong></p><p>It provides assessment at the test location only. Number of tests depends on the variability in subsurface conditions.</p><p><strong>Implementation Requirements </strong></p><p>Experience and special equipment is necessary. The equipment is patented.</p><p><strong>General Comments</strong></p><p>This test method is useful for QA.</p></p>