D 244.5 – D 508 with double head drilling units (rotary/rotary)
Piles of small diameter are designed for various applications. They pass their loads into the adjacent ground by skin friction. They can be installed with small drilling units even in constricted areas.
In many cases double head drilling units with Duplex systems are chosen for this purpose. When drilling in ground without boulders and rock bands augers are often used as the inner rod for better discharge of the cuttings. If possible, the drilling is done with auger and casing bit only.