This paper investigates the mechanics of torpedo-anchors' soil interactions in a transparent synthetic surrogate for marine clay, during both embedment and extraction. Both free falling and quasi-statically advanced torpedo anchors were included to cover a range of rates spanning three orders of magnitude (V/D of 0.2-200 s~(-1), where V is penetration velocity, and D is torpedo diameter). Impact velocities in the range of 5.0 m/s were investigated. Digital image correlation (DIC) was employed to analyze images of penetration and pullout, captured at a framerate that permitted quantifying incremental displacements. Penetration resistance was found to depend on nose shape. Two nose shapes were studied, and hemispherical noses engendered larger resistance than conical ones; however, shaft resistance is higher behind conical noses, so the combined effect on penetration of a full torpedo is minimal. Resistance in quasi-static pull out tests was the same as in quasi-static penetration tests.
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