Settlement of vertical piles exposed to waves

Abstract

In recent years, several authors have conducted experimental studies on the scour around piles fixed in the wave flume. In addition, the settlement of structures has been studied for the case of pipelines, due either to steady currents [International Journal of Offshore and Polar Engineering 4 (1) (1994) 30] or to wave forcing [Coastal Engineering 42 (2001) 313]. However, the settlement of a pile due to scour in waves has so far not been investigated.This paper reports an experimental study on the settlement of vertical cylindrical piles, either surface-piercing or entirely submerged, exposed to waves.The primary objective of the study was to investigate: (i) the scour-settlement process with piles of differing heights and densities with their bases initially lying on the seabed and (ii) the influence of the piles height and weight on the hydrodynamics vertical settlement.A series of experiments was carried out using isolated vertical cylinders of a given diameter (30 mm), different materials (PVC, aluminium, brass, copper and bronze) and different heights (30, 6 and 3 cm). The characteristics of the waves remained constant in all tests (water height = 15 cm, wave period = 2.1 s, local wave height = 4.0 cm, Keulegan -Carpenter number = 12).The cylinders were set up over a sand bed, so that they could move vertically. Both the initial settlement of each cylinder (when it occurs), due to its weight, and the evolution of additional settlement caused by flow-induced scour were measured. The tests were conducted over a period of 4000 wave cycles. D

Numerical modelling and its physical modelling support in Civil Engineering

“…Numerical modelling is not capable of reproducing the phenomena that occur in these circumstances in the way that physical modelling can. As reported in Carreiras et al (2003), experiments on the local scour produced by regular and nonlinear waves around a single pile have shown a good fitting between the equilibrium scour depth S and the Keulegan-Carpenter number. We found that it was possible to test and validate model (1), which seems to provide a good representation of the scour S.…”

“…In the field of soil mechanics, the use of physical modelling is common, especially to assess the soil-structure interaction phenomena and to validate semi-empirical models. Figure 1 Research, Society and Development, v. 9, n. 10, e5019108409, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i10.8409 6 provides a general view of an experiment of a study carried out in a laboratory by Carreiras et al (2003) to investigate the scour-settlement process of vertical cylindrical piles of differing heights and densities. The horseshoe vortex and the vortex shedding generated at the bottom, around the cylinder, induced an erosion around it, promoting sediment transport and formation and propagation of ripples clearly shown in Figure 1.…”

“…( 1)where D is the diameter of the cylindrical pile, and KC is the Keulegan-Carpenter number, as defined in Carreiras et al (2003). Research, Society and Development, v. 9, n. 10, e5019108409, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i10.8409…”

The role of scour in shipwreck site formation processes and the preservation of wreck-associated scour signatures in the sedimentary record – evidence from seabed and sub-surface data

“…Marine structures (intentional or accidental) are vulnerable to erosion due to scouring by waves and tidal currents, and scour processes can ultimately lead to the complete failure and collapse of structures on the seafloor [36,52]. Scour signatures are widely reported in marine sciences, and their development and importance in shortand long-term site evolution in coastal engineering and seabed development [7,9,13,45,29,34,36,37,39,41,46,52], glacial and geomorphological research [15,30,32,33,49,50], mine burial and detection [14,35], biology [10] and archaeology [1e 3,6,8,19,22,24,27,42e44,48,51] are commonly described in the scientific literature.…”

Scour around Piers under Waves: Current Status of Research and Its Future Prospect

“…However, studies of bridge scour at piers or piles under currents were largely reported in the literature as compared to those under waves. The scour at piers under waves was extensively studied by Sumer [4], Kobayashi, and Oda [5], Whitehouse [6], Carreiras et al [7,8], Sumer et al [9][10][11], Sumer and Fredsøe [12], Dey et al [13,14], Arabi et al [15], and many others.…”