On the bearing behavior of full displacement bored pile systems for resource-efficient optimization of these pile systems

 

Sponsor:	self-financed
Responsible:	Johannes Kuhlmann, M.Sc.

 

 

Brief description:

In the installation of full displacement bored piles, the drilling tool is turned into the ground without any relevant soil extraction and without causing vibrations. Then, while simultaneously pulling the tool, the pile is concreted out. This production process completely displaces the soil in the vicinity of the pile shaft and compacts it at the same time. This leads to an increase in load-bearing capacity compared with conventional bored piles. In Germany, two full displacement bored pile systems are predominantly marketed, the "Fundex" type and the "Atlas" type. However, there are a large number of other full displacement bored pile systems that differ greatly in their manufacturing process, the design of the drilling tool and the load-bearing capacity. The aim of the research project is to optimize the system of full displacement bored piles with regard to a more economical and sustainable design. Two sub-aspects are decisive in this respect. On the one hand, a deeper understanding of the soil mechanical processes during the production of screw piles is to be achieved. In this context, the influence of the manufacturing process on the bearing behavior is to be investigated and the optimization potential of different pile systems is to be worked out. The existing pile systems will be further developed in the scaled physical and numerical model. The aim is to increase the load-bearing capacity by modifying the drilling or cutting tool. It is important that the installation capability of the pile is maintained. The further developed drilling tool will then be tested in field trials. On the other hand, the planned research project is intended to help quantify the increase in load-bearing capacity and implement it in the design. For this purpose, it is necessary to derive the relative improvement of the bearing capacity with respect to the known initial system (system "Fundex" or "Atlas") for different system boundary conditions. The results are then to be transferred into a standardized process applicable to different full displacement bored pile systems.