Vibratory Emplacement of Small Piles.

Abstract : An experimental study was conducted to evaluate vibratory emplacement techniques for small piles. A vibratory pile driving system utilizing a hydraulic piston actuator was designed, assembled, and tested. The general effects of driving frequency, surcharge, driver power, and tip driving were evaluated. Tests were conducted to compare the vibratory driving with impact driving. Although rapid penetration rates were achieved with the vibratory system, this advantage was minimized due to the short total driving time. Therefore, it was concluded that a small vibratory pile driver must compete with impact hammers in size, portability, and efficiency. A large system surcharge appeared to be an inefficient method of achieving penetration in difficult terrain. Instead, it was recommended that a linkage be designed to provide rapid impact capability for the actuator in difficult conditions. A small, self-powered, hydraulic system of this type could perform several construction site tasks. The vibratory capability could be used to rapidly emplace or extract piles, stakes, and ground anchors. The rapid impact mode could be used to penetrate difficult soils and to carry out various demolition tasks. (Author)