Structural verification of the repair planning
The Dhrontalsperre lies approx. 20 km east of Trier and is part of the Drohn-water power plant in Leiwen. The dam was errected by the electric company of the city Trier in the years between 1911 and 1913. It has been maintained by RWE for a long period of time. The Dhron-power plant utilises the height difference (approx. 100 m) between the small Dhron and its estuary into the Mosel with an installed power of 8 MW.
Within the scope of comprehensive maintenance in the year 2005 and 2006, the structural stability of the perfused cordoning structure was restored again. The remaining, pending reinstatement of the cascades, return walls and the stilling basin are part of this project. The reinstatement serves the longevity.
The cordoning structure made of crushed stone masonry is formed as a curved weight dam wall. The damn wall has a height of 20 m above grounding foundation floor and a crest length of 95 m. On the air side of the dam wall, the cascades are arranged in order to supply the stilling basin with overflowing water. On the right side, there are 6 cascades, whereas on the left there are 7 cascades present.
The height difference between the individual cascade levels amounts to 2.05 m - 2.15 m on the right side and 1.84 m - 1.88 m on the left side. The fall height to the stilling basin amounts to approx. 3.0 m.
The reinstatement of the cascade and return walls was performed through the application of a shotcrete layer (h = 15 cm) via crosswise reinforcement. After that, it was back-anchored with a connection anchor. The sole of the stilling basin also received a back-anchored grout topping layer with a thickness of h = 15 cm.
ZPP operated as structural design verification engineer (verification engineer: Dr.-Ing. Dieter Lehnen).