Showing papers by "Adrian Wing-Keung Law published in 1995"

Initial Gap in Breakout of Half-Buried Submarine Pipe Due to Wave Action

Abstract: An analytical formulation is presented for the analysis of the breakout of a half-buried submarine pipe due to wave action. The formulation accounts for the contact between the pipe and the soil due to the horizontal hydrodynamic force. An asymmetric gap geometry is described that incorporates a second order expansion in the gap opening due to the pipe rise. Results with this formulation demonstrate the existence of an initial gap of the order 1 mm in the breakout experiments. With this initial gap, the gap flux dominated the influx of water into the gap from the beginning of the breakout process.

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.