The Force Exerted by Surface Waves on Piles

Abstract

t Experimental data for the foroe distribution on three model oylind-rioal piles for three nave conditions.are presented. These results are compared to the previously published theory.**' Introduetiom The purpoao of this report is to present experimental data on the foroe distribution exerted by surfaoe waves on piles* From these data the ooeffioients of drag and mass that appear in the equation**' for the foroe were obtained* The experimental results were compared to the calculated foroe distribution* In order to simplify the presentation, the foroe (lbs) was divided by the projected area (ft 2) of a segment of the pile to give a foroe intensity (lbe/ft 2). The measurement of foroe was made on a one-inoh'high segment of several model piles of various diameters* The results of these studies are that the experimentally determined coefficient of mass shows good agreement with the theoretical value of 2*oC 7 » 8), and relatively good agreement with the values in previously presented experiments(1#2,3,4,5,467. The results also show that the experimentally determined ooeffioient of drag is in relatively good agreement with the value 1*6 as found in previous experiments(^» 2 » 5 »*»* 6 '' The measurements of the foroe intensity distribution showed good agreement with the oaloulated distribution using the previously mentioned values of the ooeffioi-ents in the equation for the foroe*

Design of monopiles for offshore wind turbines in 10 steps

“…Long and Vanneste (1994) give a good account of the research efforts into the analysis of piles under cyclic lateral loading by modified 'cyclic' p-y curves. Improved p-y curves for cyclic lateral load were developed by Reese et al (1974), O'Neill and Murchinson (1983), Little and Briaud (1988). More fundamental theoretical approaches have been attempted by Swane and Poulos (1982) as well as Matlock et al (1978).…”

“…A simplified approach to wave load estimation is Morison's (or MOJS) equation (Morison et al 1950). In these equations the diameter of the substructure is taken as = + 2 + 2 [ ] to account for the transition piece (TP) and the grout (tG) thickness, as given in Section 2.1.5 in Equation 9.…”

“…The approach can be found in API (2005) and also suggested in DNV (2014). Originally it was developed by Matlock (1970); Reese, Cox, & Koop (1975); O'Neill & Murchinson (1983) and the basis of this methodology is the Winkler approach (Winkler 1867) whereby the soil is modelled as independent springs along the length of the pile. The p-y approach uses non-linear springs and produces reliable results for the cases for which it was developed, i.e.…”

Influence of Floater Response on Wind Turbine Tower Moments in Floating Wind Turbine System

“…The scheme uses Morison equation [ 17] with Srinivasan's Model [ 6] for estimation of hydrodynamic force, non-hydrostatic model [ 14] for restoring force and penalty method [ 18] for contact of mooring with seabed. The equation of motion can be written as…”

On the Force Decompositions of Lighthill and Morison

“…Among them, sinusoidally oscillating #ow about a circular cylinder or the sinusoidal motion of a cylinder in a viscous #uid otherwise at rest has been of special interest to o!shore engineers for at least half a century. Morison et al (1950) proposed a force decomposition, for the determination of wave force on a &&cylindrical object'', which may be written as…”