1. Use a driving head (or cap) compatible with both the hammer and the pile. Concentric alignment and proper dimensioning will transfer energy more efficiently and minimize damage to the butt of the pile. A tapered cone (6″ - 12″ long) providing a close internal fit facilitates entry and holds the pile butt centered for axial alignment.
2. Maintain axial alignment of adjoining sections. Monotube tapered and extension sections can be
- shop-assembled to custom lengths (subject to shipping limitations)
- rack-assembled on the job site
- spliced in the leads
When splicing in the leads, the weight of the hammer is usually enough to assure a snug fit prior to welding. (Never fire the hammer!) The self-aligning telescopic Monotube splice shown facilitates axial alignment.
Use welding electrodes compatible with chemical and physical requirements of the joint. E6010 and E6011 rods are recommended for adequate penetration of the root pass. Alternatively, an E7018 rod may be preferred by a welder experienced in its use. Quality welds are critical to the ultimate performance of the driven pile.
Closely monitor resistance when approaching bearing on high capacity piles requiring final blow counts on the order of 10 per inch or more. Prolonged driving at rapidly escalating blows can damage both the pile and the hammer.
Extensions can be welded to tapered sections or to other extensions as required. “N” sections are furnished longer than nominal lengths to provide for a telescopic splice.
Continuous Fillet Weld
Cut-off Extensions Field Crimping Detail
Burn or cut slits in valleys.
1. For 7 and 9 ga. piles, slit alternative valleys.
2. For 5 and 3 ga. piles, slit every valley
Crimp with tool or use sledge.
Insert cut-off and seat into pile to be extended and weld.