Subsea Installations Using Vibratory Piling Hammers

Abstract

During the summe~of 1987 ICE hydraulic vibratory hammers were used 3 times successfully for subsea installations of anchorpiles and template foundation piles. The hammers proved to be, for the soil conditions encountered, a suitable alternative to conventionally used impact hammers. The present paper will briefly describe the results .of the driveability studies on the basis of which the hammers were accepted and give full details of the three projects. The installations also proved that for the combination of small diameter piles and oyerconsolidated clays, pile plugging may occur. and has to be. taken into account in pile drive-ab~lity calculations. The second part consists of the description of the extension of the stresswave programme TNOWAVE for vibratory hammers and iQ.which case this programme can be of great help to judge the reliability of the vibratory pile driveability studies.

30 Years of Experience with the Wave Equation Solution Based on the Method of Characteristics

“…A long pile is not moving as a single lumped mass, and stress wave phenomena have to be taken into account. Using the method of characteristics the VDPWAVE module was developed, and following its release in 1988 it was used to demonstrate that long offshore piles could be installed with vibro-hammers (Jonker & Middendorp, 1988).…”