Cost effective solution using a standard excavator
Possibly the largest retention basin in Austria is currently being built in Triestingtal (Lower Austria). Engineers at PORR were given the task of installing a diaphragm wall along the centre line of the dam during the construction phase. For this project it was decided to try a KSI injection attachment from the German manufacturer KEMROC. This modified excavator trenching tool digs into the ground, mixes the soil and injects a cement suspension into it. After hardening, what is left is a pressure resistant, impermeable soil cement structure closely connected to the adjacent rock.
In the future, when the Triesting, a river flowing through south-eastern Wienerwald in Lower Austria, floods again after heavy rains, as has so often happened in the past, people living around Fahrafeld in the district of Pottenstein should find themselves better protected from the flood waters. A massive water retention basin is being built there for this purpose. With a capacity of 725,000 m³, the basin is intended to protect the community and the infrastructure from those once in a 100-year flood event. The construction company PORR is currently building a dam, approximately ten meters high, to hold the flood water. The dam consists of two side sections about 1,300 m long with the basin located between the riverbed and railway lines. The sides are connected to one another with a transvers dam about 150 m long. The main structural element of the dam is a diaphragm wall made of a soil cement mixture which is firmly anchored into the solid rock below the dam.