Bauer Spezialtiefbau has been commissioned by HT Generalunternehmer & Industriebau to carry out measures to secure the deep excavation and to build a king pile wall and deep foundations for supports.
The deepest drillings went down to 36m. Given the tight schedule work started with the piling works even before the existing structures had been fully demolished. In addition, a great deal of work had to be carried out in parallel, so that the works had to be undertaken in an extremely confined space despite the actually large construction site of around 3,500m².
To be able to meet the tight time constraints, a Bauer BG 40, a BG 30, a BG 28, and, for a short period of time, a BG 23 were used.
Special excavation chambers were planned as a result of the underground line 3 that crosses the construction soil at a depth of 16m, to minimise the construction soil relief and the associated potential ground heave. For this purpose, drillings were executed into which the HEB steel beams were fitted into the gravel. Afterwards, they were connected with sheet piles to form a wall.
Overall, around 5,100 running meters of in-situ concrete piles and around 5,400 running meters of drillings were created for the king pile wall within a period of eleven weeks.
Thanks to the high flexibility of the executing team and the good cooperation between the individual firms, it has been possible to complete the main services ahead of the planned completion date.