Institute for Geotechnical Engineering Research Research Projects
Longitudinal Joints of Wooden Poles and Displacement Piles

Longitudinal Joints of Wooden Poles and Displacement Piles

Led by:  Prof. Dr.-Ing. M. Achmus
Team:  B. Sc. Maria Müller, M.Sc. Junnan Song
Year:  2020
Funding:  Bundesministerium für Ernährung und Landwirtschaft (BMEL, Federal Ministry of Food and Agriculture)
Duration:  01.01.2020 - 31.12.2024


The overall objective of this project is to make use of previously unused potential of regionally available durable timber qualities. Therefore, a friction-locked, durable and easily manageable longitudinal joint for wooden piles in hydraulic engineering is to be developed and constructed, which makes it possible to join individual pile sections to form a fully load-bearing pile of any length. By joining individual pile sections, waste wood (timber for hydraulic engineering) can be put to a new use by processing intact pile sections and joining them to new piles of sufficient length. Damaged piles do not have to be replaced completely, but only in parts, so that intact areas remain and can continue to be used. In addition, the use of indigenous timber can become competitive again, as durable heartwood sections can be joined to form timber piles with high and almost constant durability and load-bearing capacities over a theoretically arbitrary length. 

In the project, suitable longitudinal joints are being validated and evaluated in extensive climatic, static and dynamic test series. On-site tests carried out under realistic working conditions are to prove the practical suitability under various realistic boundary conditions. This will be accompanied by the implementation of a load model and a finite element model for the dimensioning as well as the development of practical recommendations for potential users. For the use of waste wood, the development of a procedure for the selection of dismantled hydraulic timber with regard to reusability is also planned. A special focus must be placed on the driveability of the joined piles, as piles in hydraulic engineering are usually installed as so-called displacement piles by percussive or vibratory driving.