Screw piling: still a challenging discussion topic?

摘要

The screw piling technology development has followed a bumpy road from its early days more then a century ago, with the first trials in France of cast iron (small) diameter screw pile systems, to about 25 years ago when implementing the well accepted "first generation" type of cast in situ screw piles. A market leading type of "auger" pile, already from this early stage of screw piling, remained until today, the well known CFA type of auger pile. In this piling technology a large variety of important installation parameters has been recognized and well improved since then. Basically however the CFA piles, in view of their load-settlement behaviour, remain to be classified in my views as bored pile systems, (table 1). The challenges of improving the quality level of displacement screw pile systems (fig. 1), have brought us today already to the "third' generation of the screw piling technology (table 1), implementing systems with a broad scope ol highly sophisticated displacement auger head shapes (fig. 2) capable of optimising the required penetration energy (torque and thrust) in various type of soils, while easily adapting concrete casting procedures.