In October 2008, a project description where 700 mm wide AZ steel sheet piles were installed with an hydraulic press was published in this ‘news’ sections.
This report describes another project where the ‘Silent Piler’ from Giken pressed much longer sheet piles into the ground.
The ‘Müritz- Elde’ canal passes through the German city ’Neustadt-Gleve’. A lock and a weir called ‘Wulfenwehr’ are within the limits of this city. The concrete weir was built in the late 19th Century, and rehabilitated in the 1970’s.
Nevertheless, beginning of the 20th, it was in a very bad shape. The Waterways and Navigation Authority of Lauenburg, which is in charge of the maintenance of the waterways, decided to rebuild the weir.
Figure 2: AZ 37‑700 pressed almost to final elevation
The tender documents were finished by mid 2008, and the works at the job-site started in October 2008.
The project was split in two phases: the construction of a new weir between the existing weir and the adjacent housing complex. This weir was erected inside a rectangular steel sheet pile cofferdam. Phase two started After finishing this first portion of the project, it consists in dismantling the old weir and building the second portion of the new weir. Similarly, this is done inside an impervious sheet pile construction pit.
Two main constraints guided the choice of the installation method of the steel sheet piles to hydraulic pressing: the stability of the existing weir, which might have collapsed if the vibrations during driving were too high, and the noise and vibration issues to be avoided due to the very close housing complex.
The sheet piles had to be driven into a deep-seated impervious layer, overlain by a relatively dense soil layer. The chosen solution was pre‑boring along the axis of the sheet pile walls down to approximately 0.5 m above tip elevation, and to replace the excavated soil by an adequate fill. This allowed the sheet piles to be pressed down to final grade without any problems or vibrations.
Due to the requirement of penetrating into the impervious layer, the sheet piles installed in the cofferdams had to be up to 21.75 m long. The design of the sheet piles required an elastic sections modulus ranging from 2 700 cm³/m up to 3 700 cm³/m. Consequently, the natural choice for this type of application was the wide AZ 26‑700 and AZ 37‑700 sections. All the loading cases, including the ‘installation’ case, could be verified with theses sheet pile sections.
Figure 3: Hydraulic press equipment (limited working space)
This was the first time that the new model ‘ECO 700S’ from Giken was used in Germany. One nice feature is that it can press Z‑piles up to 700 mm wide (AZ‑700 range) as well as U‑piles up to 750 mm wide (AU range)
This was quite helpful when, as specified on the layout, the driving contractor had to close the cofferdam with a single PU 32 sheet pile, a 600 mm wide U‑pile. No additional equipment was required for this task.
Wasser- und Schifffahrtsamt Lauenburg
Otto Heil GmbH & Co. KG, Taucha
Giken Europe BV, Berlin
328 t AZ 37‑700, 11.50 to 21.75 m long
223 t AZ 26‑700, 11.50 to 21.75 m long
1 single pile PU 32
4 t various special connectors (C9, C14, etc)
S 240 GP, S 355 GP
Released on 13/01/2009