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Excavation for Sächsische Aufbaubank (Development Bank of Saxony)

Photo: Aerial shot of the excavation site in Leipzig city centre, surrounded by multi storey buildings. Several large and small machines are involved in the foundation and preparation of the excavation pit.
Facts and Figures
Company FRANKI Grundbau GmbH & Co. KG
Principal.
LocationLeipzig - Germany
Type Specialist civil engineering

Complete excavation for Sächsische Aufbaubank

Sächsische Aufbaubank (Development Bank of Saxony - SAB) is moving its head office from Dresden to Leipzig. Just a stone's throw away from the central station in Leipzig, and between two hotels, a new office and commercial building (including an underground car park with approx. 175 parking space) is being constructed on a site measuring around 10,000 m².

FRANKI has teamed up with Günter Papenburg Verkehrswegebau GmbH for this complex construction project. GPV is responsible for the ordnance investigations, the excavation work and water pumping. FRANKI is responsible for excavation drilling and the creation of the excavation pit. Our subsidiary isg carried out the plant and construction planning, whereby the originally planned 1 m thick sealing wall could be altered to a thickness of 0.8 m, in order to reduce costs.

At depths of approx. 7 m, the waterproof excavation pit should be designed with a 30 m deep sealing wall with integrated sheet piling, which should be incorporated in the shell limestone. At depths between 11 and 16 m, there are quartzite layers of various strengths and depths.  These must be removed by excavation bores along the sealing wall. For this purpose, the route clearance with overlapping bores (d = 1.5 m with a depth of up to 19 m) was tendered by the building owner.

The work was complicated by the contamination of the groundwater and the extremely abrasive and very inhomogeneous properties of the quartzite, which led to a high degree of wear to the drilling tool used. The large drilling diameter and the coal resources also posed great challenges in certain areas. Due to the tight time frame and the challenges mentioned above, the evacuation wells were drilled using four rotary drilling devices, and the sealing wall work was carried out using three cable excavators. In parallel to the anchoring and excavation work, an existing building, covering approx. 5,000 m², was demolished. The inner-city project presents a logistical challenge for everyone involved, due to the use of several large devices and a large-scale water treatment plant. At this point, we would like to thank everyone involved in the project - particularly all of our employees on the construction site - for their good cooperation.

Services:

  • 12.000 m² sealing wall, d = 80 cm, t ≤ 30 m
  • 400 excavation bores, d = 150 cm, t ≤ 19 m
  • 4.000 m² sheet pile, L ≤ 11,70 m
  • 144 temporary multi-strand anchors, Zk ≤ 590 kN, L ≤ 20,5 m