| 摘要 |
A core barrel has a plurality of pneumatic downhole hammer drills disposed around the perimeter of its working end for drilling piles in the ground for use in foundations, secant piles, and the like. The core barrel includes a slurry port and an air port at its top end for admitting a drilling slurry and pressurized air, which is used in driving the hammer drills and flushing cuttings from an annular kerf during drilling. A plurality of generally parallel plates form the top of the core barrel and define an air channel and a slurry channel for delivering air and slurry to the core barrel wall, where they flow freely or via conduits toward the hammer drills at the working end of the core barrel. The hammer-type core barrel is used to construct piles by first drilling an annular kerf in the ground. Circulating drilling fluid cools the working end of the hammer drills elements and washes cuttings from the kerf during drilling. The drilled core may be removed, or it may remain in situ, with the kerf being filled by cementitious material or by a structural steel casement.
|
