Incipient Fluidization of Fine Sands in Deep Seabed

Abstract

The pore pressure increase in a deep sandy seabed due to the discharges from a buried source pipe was studied analytically. Darcy's law was assumed. The injection flow from the discharge ports of the source pipe was simulated as line discharges. An analytical solution of the pore-pressure increase was obtained using the technique of conformal mappings and the method of images. The pore-pressure distribution was analyzed for a burial depth 5–20 times the pipe diameter. The results indicated that the effect of the pipe size was confined to a distance from the center of the pipe of approximately half of the burial depth. Based on the analytical solution, the flow rate for the incipient fluidization of the cover sands was determined using the fluidization criterion adopted in 1990 by Lennon, Chang, and Weisman.