Is Scour Important for Pile Foundation Design in Deepwater?

Abstract

Since strong bottom currents with long durations have been observed in many deepwater developments, scour hazards may become a serious concern which can have major consequences for pile foundations and associated equipment. While bridge scour has been studied and well documented, offshore scour prediction remains an uncertain art. In most cases, local experience is relied on as the best guide for scour prediction, and an operating strategy of monitoring and remediation is considered necessary. This can result in excessive contingencies and design allowances and the need for expensive and time consuming monitoring. In this paper, selected bridge scour concepts are extended to apply to deepwater pile scour prediction after necessary modifications. Pile behaviors with the presence of scour are studied, to identify the sensitive scour range for various types and sizes of offshore piles.

Effect of Scour on the Natural Frequency Responses of the Meteorological Mast in the Taiwan Strait

“…The seabed in the vicinity of large-diameter (D > 4 m) monopile foundations subjected to waves and currents can be scoured by horseshoe vortices [15][16][17][18][19]. DNV [20] and DNV GL [9] recommend a scour depth of 1 to 1.5 times the pile diameter for the monopile foundation design.…”