Experiments were designed to study the terminal phase of penetration in a synthetic soft clay. Rod-cone projectiles were launched at speeds of approximately 5 m/s into a saturated soft transparent surrogate for saturated marine clay. Quasi-static tests were also performed into the same material. The average penetration resistance was 22 kPa. It was found that rate effects and shaft resistance were relatively small. A practical result is that resistance to dynamic penetration in this material can be estimated from quasi-static cone penetration tests. The stress (load/area) required to extract penetrators was very similar to the penetration resistance.

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