Bauer has said that work on installing a diaphragm wall to renovate a hydroelectric dam in south Germany is progressing well and expected to finish on time next spring.
2018 11 bauer rosshaupten dam renovation work 2
The Rosshaupten barrage was built in the 1950s and there were concerns over the water-tightness of the structure on the 45MW hydroelectric facility which has led to the current remedial work.
Bauer started work on the scheme for Uniper Kraftwereke in May this year and is installing a 13,500m2 diaphragm wall to create a full cut off.
Work is being delivered from the 11m wide dam crest and the space constraint tis further challenges by the diaphragm wall alignment being offset within the crest rather than in the centre. Bauer is using
A Bauer HDS-T turnable hose drum system to deliver the work within the constrained site.
The 1m wide and 70m deep diaphragm wall is being constructed in two stages. First the upper 40m of the dam body will be excavated using a DHG diaphragm wall grab on a Bauer MC 64 duty-cycle crane. The remaining 30m below the actual dam fill will be removed using a cutter BC 40.2 on a MC 96 duty-cycle crane.
“The local bedrock consists of many and often very thin layers of clay stone, marl clay and sandstone,” said Bauer project manager Ralf Meyer with regard to the two stage approach.
According to Bauer, another special feature of the project is the guide wall for the execution of the diaphragm wall work. A mixed-in-place wall approximately 550m wide and 8m deep was installed this summer using cast-in-situ concrete casing to ensure optimal guidance of the machines during work.
Work is being undertaken 24 hours a day, seven days a week to meet the spring 2019 completion date.