On the loss of contact between driving element and soil during vibratory driving into saturated soil
The vibration driving of piles is a tried and tested method of driving the pile into the ground quickly and economically. Compared to other methods, vibration pile driving represents a relatively low-vibration and low-noise introduction of the pile. Current studies show insufficient agreement with the observations and interpretations of corresponding experiments. When moving upwards, a cavity can form under the pile base. The nature of this presumed void is not fully understood. In addition, the separation between pore water and soil particles and a possible phase transition of the pore water to water vapor (cavitation) due to the negative pressure have not been adequately researched. The cavitation pressure required for this is achieved when the pore water cannot flow into the cavity with sufficient speed due to the permeability of the soil. The main aim of the research project is therefore to clarify the processes at the pile base during the upward movement during vibration driving and the influence of the subsequent static load-bearing behavior through the installation process. Another aim is to investigate the influence of physical cavitation and the suspected cavity under the pile base during vibration driving. For this purpose, computer simulations are carried out, which are validated with the help of model tests.