The extension of the A100 is intended to better connect the eastern districts of Berlin to the central ring road and the A113 motorway. An important milestone was already reached in November 2022 with the commissioning of the Ringbahn bridge. The team is currently working on the construction of the 225-metre-long road tunnel, which will later lie at a depth of up to seven metres.
Groundwater poses particular challenges
One of the biggest challenges of the project was that the construction work for the road trough had to be carried out in the area of the groundwater. Trough excavation pits had to be constructed in order to prevent damage to the surrounding area caused by large-scale groundwater subsidence. For this purpose, construction pit walls were made from diaphragm walls. The underwater concrete base is anchored back with threaded anchor piles against the uplift forces. Specialist divers were deployed to ensure the work was carried out safely under water. In September 2023, the trough construction pits were drained after successful pumping tests, which proved that the specified tightness criteria had been met.
Trough structure in progress
The actual trough structure for the future motorway has been under construction since September 2023. The three transverse bulkheads have already been successfully dismantled and the trough base of the three closing blocks has been completed. Intensive work is currently underway to realise the trough.
