| 摘要 |
<p>In a method of sub-sea pile-driving in ultra-deep water a pile (200) releasably suspended from a deck structure (32) carried by a suspension rope (2) from a floating craft is lowered until a base structure (236) rests upon the sea bed (53). A mooring rope (276) paid out from the craft is connected, via a mooring chain (270) releasably connected to and partially fleeted upon the structure (236), to a releasable mooring collar (258). A guide tube (38) receives a pile-driving hammer of which the upper surface is exposed to the ambient sea, and a pile-driving anvil which is at the top of the pile (200). Defined by the tube (38), the hammer and the anvil is a water-tight chamber whereby raising of the hammer in the tube induces a negative pressure in the chamber which ensures that substantially all of the hydrostatic force on the hammer is employed in striking the anvil and thus driving-in the pile (200).</p> |
