U.S. Geological Survey Open-File Report 03-221
A Pictorial Survey of the Bedrock Beneath Western Cape
Cod, Massachusetts
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Photograph shows the sonic drill rig with the drill casing partially penetrated. The sonic vibratory action fluidizes the soil particles, destroying the shear strength and pushing the particles away from the tip of the drill bit and along the sides of the drill string. This liquefaction process allows for clean, rapid and smooth penetration of overburden formations. The advantages of sonic drilling are superior drilling speed, good recovery of undisturbed, and large diameter core samples.
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