Fastening in a flow

Hydro power plant renovation in Biessenhofen with FIS EM injection mortar system from Fischer

Fastening in a flow
The renovation work proceeded quickly – until frequent flooding damaged the temporary dam in the river Wertach, which was filled with gravel. This was set up in consultation with the responsible nature conservation authorities. All attempts to keep the water away from the defence system using “big bags” - one cubic metre of plastic bags filled with gravel – were unsuccessful. Further flooding caused the level to rise so much that the locks were opened and the water supply was damaged several times.
For example, the further work in the area of the defence facility on the side facing Lake Bärensee had to be put on hold. In the Bachtelsee direction, the pillars and walls around the turbine inlet had to be renovated. VWEW-energie overcame the challenges of floods as the operator and developer, on the proposal of the engineering office Dr. Ing. Koch Bauplanung GmbH and with the cooperation of the commissioned dive master company Kerlen Taucher GmbH, by having a new reinforced concrete wall erected. This was installed after the previous dam and measures approx. 2 m thick and 9 m long. After “pulling up”, the reinforced concrete wall in combination with a needle closure will separate the river Wertach from the working areas.

Property description

Building owner:
VWEW energy
Construction planning:
Engineering Offices Dr. Ing. Koch Bauplanung GmbH
Project scope:
Hydro power renovation
Diving companies
Diving master company Kerlen Taucher GmbH
Our fisher FIS EM injection mortar has approval for water-filled drill holes according to anchor theory to suit the application
Bernd Wetzel (fischer application mechanic)
The specialists erected the wall by fixing concrete steel B 500B to an existing floor slab with the FIS EM 1500 S injection mortar in combination with connecting sleeves with a diameter of 20 mm. The material used, which complies with the ISO and Swiss SIA standards, has the property that it is highly ductile and can therefore deform plastically under load before it fails.
In this way, the 25 cm diameter holes were successfully filled with the injection mortar and the concrete was secured with the system. “Additional advantages are that the solution, along with other system components, is specially suited for reinforcement connections from 8 to 40 mm diameter in concrete and offers high load values,” adds the state-certified construction engineer. “The system temperature of up to 5°C is also suitable for underwater installation.”
There was no normal concrete as the substrate. In the run-up, Bernd Wetzel and employees of the construction company Xaver Lutzenberger GmbH & Co. KG undergoes extensive tests. By means of pull-out tests, the experts tested the load-bearing capacity of the installed system consisting of FIS EM injection mortar, reinforcement rod and concrete using a rock anchor test device at 200 kN tensile force, which was determined in coordination with the engineering office Konstruktionsgruppe Bauen AG. For this purpose, the employees of Lutzenberger GmbH sailed over the anchoring points in a boat. They used a reinforcement sleeve as a connection to extend the bars and fitted a steel pipe on top of them. The test device was placed on it and pulled.    
We generally only use fisher products for underwater installation
Karl Kerlen (from Kerlen Taucher GmbH)

To avoid the risk of the FIS EM cooling down and becoming tough due to the low water temperature, it was heated before installation. The commissioned construction divers from Kerlen Taucher GmbH, who had previously made the drill holes, then informed Bernd Wetzel via Funk if they needed more mortar. The fisherman then injected it via a hose on call and the construction divers filled the boreholes with it. In this way, the defence system was successfully dried and reinforced. “When using the Fischer injection mortar system to reinforce the reinforced concrete wall in Wertach, for example, we can be absolutely sure that it will withstand the extreme conditions,” emphasises Karl Kerlen from Kerlen GmbH.
The result was a stable reinforced concrete wall, which makes it possible to repair and maintain the function of the 60s plant – and ultimately the ecological generation of electricity from water.
cd-blue-54ff7c8c74-l2bc7