Experimental study on irregular wave-induced pore-water pressures in a porous seabed around a mono-pile

Abstract

In this study, a series of physical model tests were carried out in a wave flume to study the pore pressures around a mono-pile under irregular waves. The mono-pile was installed to the position of 0.6 m below the seabed surface. The main purpose of this study is to analyze the distribution of pore-water pressure around and beneath the mono-pile under irregular waves. Five different wave spectra were used in the tests. The experimental results conclude that: (1) the pore-water pressure around the pile increases as the increase of significant wave height and period; (2) the maximum pore-water pressure decreases as the increase of seabed depth (z), this trend is significant near the seabed surface (z ≥ −0.3 m), and the influence is not obvious for the region below 0.3 m; (3) at the depth of 0.15 m below the seabed surface (z=−0.15 m), the maximum pore pressure occurs in front of the pile, and at the depth of 0.1 m below the bottom of the pile (z=−0.7 m), the maximum pore-water pressure occurs behind it; (4) the irregular wave-induced seabed response is larger than that of the representative regular wave; and (5) the irregular waves with Pierson–Moscowitz (P−M) spectrum introduce the most significant seabed response among various wave spectra.