Designing PULSE and BLUE blow generators for experimental research in the geotechnical centrifuge

The next generation of monopiles for the offshore wind market will exceed 12 m in diameter. These foundations will
facilitate the transition of bottom-founded offshore wind mills into deeper waters as well as enable the installation of
larger turbines. There are questions whether conventional dynamic installation techniques can be used to install these
foundations, mainly due to challenges related to sound emissions and fatigue. New dynamic installation equipment,
that rely on the prolongation of the impulse duration, are therefore under development. PULSE and BLUE technology,
both developed by IQIP, are examples of such equipment. Both strive to reliably drive large monopiles while
drastically reducing sound emissions and fatigue manifestation. However, little is known about the practical
implications of impulse prolongation of pile-soil-water interaction, which plays a critical role during installation. To
study this, Delft University of Technology (DUT) is developing the hardware required to simulate the installation of
monopiles with PULSE and BLUE technology in the centrifuge. By fitting a 16.4 mm syntethic polymer buffer
between the hammer and the anvil, PULSE-blow characteristics can be replicated. The resulting system can be installed
by DUT’s miniature electro-mechanical pile driver. To simulate a BLUE-blow, the anvil is fitted with a stiff linear
spring. For installation a dedicated actuator used which is currently under development. Both designs are verified by
means of numerical simulation.