Upgrading the Oder Dam. Sections of the dam have been successfully renovated with PASCHAL systems.

The Oder dam is a dam in the western Harz mountains. It is located near the town of Bad Lauterberg in the Osterode district. It mainly serves to regulate the water flow (flood protection and spillway, low flow elevation) and to generate power.

Regular installation upgrade

The Harzwasserwerke GmbH (HWW), based in Hildesheim, is the largest water supplier in Lower Saxony and one of the ten largest water suppliers in Germany. As well as providing drinking water, the company's key duties involve flood protection and low flow elevation. For this, it uses the natural drop between the dams in the Harz mountains and the supply areas in the Harz foreland to generate hydraulic energy without harming the environment.
HWW managers therefore ensure regular and timely upgrades to the installation, and recently arranged for a section-by-section general overhaul of the Oder dam to obtain an installation that is as good as new.

Structural upgrade to spillway after 80 years.

The spillway that protects the dam structure in the event of extreme floods is integrated in the main dam of the Oder dam. The spillway, located on the south, left-hand side of the Oder dam, which was constructed between 1933 and 1936, is composed of an inlet structure with an overflow and a collecting channel, a bridge over the spillway and a chute that includes guide walls. The chute leads to the underwater basin of the Oder dam.

The spillway measures approx. 335 m in total and has a maximum longitudinal incline of 17.5 degrees. The average width of the floor of the collecting channel and chute is 5.00 m.The bridge construction carries the causeway over the spillway collecting channel.
On the south, slope side of the collecting channel, the causeway is supported by a gravity wall connected to the bridge construction.

A key part of the general overhaul of the dam was the restoration of the whole spillway structure, of which significant sections were dismantled and then rebuilt. In the course of the restoration work on the collecting channel, the causeway was also extended by about 80 m behind the inlet structure.

The LOGO.3 formwork system used for the chute renovation in the middle section. The inclination of the floor, which follows the side walls, averages 17.5 degrees. The formwork is between 2.70 and 3.40 metres high. The whole chute construction was concreted in alternance (pilgrim method) with concreting sections of approx 10.00 m.

An experienced duo

Bernd Schulze, the site manager responsible for this project, and his colleague Jens Rabenau from the planning process are an experienced duo from Umwelttechnik & Wasserbau GmbH, who have successfully realised numerous concrete structures and constructions using PASCHAL systems. The longstanding collaboration between the implementing construction firm and PASCHAL makes for a great team.

For the construction work on the Oder dam, the construction firm expanded its existing PASCHAL formwork material with further rental equipment from the Steinach formwork expert.
After the initial formwork planning, a highly valued service package also provided by PASCHAL for this project, around 400 m² of the LOGO.3 formwork system, approx. 150 m² of the "TTK" circular formwork system, 50 m² of LOGO alu wall formwork and 50 KBK single brackets were brought to the site in the Harz mountains.
These systems enabled the very different and diverse restoration works to be carried out as planned on the engineering construction.

Harzwasserwerke specified that the concrete quality had to be highly resistant to water with an even, smooth and non-porous surface (SB 2, SHK 2). The plywood surface were therefore coated on site with Zemdrain. The coating on site has been done without any difficulties, leading to the required surface result on the newly built reinforced concrete structures.

PASCHAL systems make easy work of curves, inclinations and topographical adjustments.

The TTK circular formwork system was used as single sided for concreting the collecting channel on the slope and adjusted precisely on site at the specified inclination and at the requested radii.
For the higher formwork levels, KBK single brackets were used to supplement both the TTK  and LOGO.3 to ensure a safe and efficient construction process.
The LOGO.3  and LOGO alu formwork systems were used both to form the floor and to produce the straight wall sections on the level and for the up to 17.5-degree channel incline.
The new construction of the collecting channel and chute was more than 50 metres long and was concreted in alternance using the pilgrim method. In addition to following the exact course of the channel, this required the correct installation of the previously integrated rock anchor bolts and water stops. And all this within a rather ambitious construction schedule that envisages the completion of all the general dam overhaul works in 2018.

Parties involved in the construction project

Contracting authority/client:
Harzwasserwerke, Hildesheim

Construction firm:
Umwelttechnik & Wasserbau GmbH, Blankenburg, Magdeburg branch

Structural engineer:
Dipl.-Ing. Ulrich Weißwange, Aschersleben

Formwork planning and formwork supplier:
PASCHAL-Werk G. Maier GmbH, Steinach

Formwork planning of chute in concreting section BE 16.

Construction drawing for the renovation of chute Lot 7 on the Oder dam.