Liebherr slurry wall cutter takes on Munich’acs largest construction project

The suburban railway in Munich was opened for the Olympic Games in 1972 and has now reached its limits. The railway will find its feet again thanks to the expansion of the rail network, Munich’s largest construction project for the coming years.

In order to cope more efficiently with the bustling stream of passengers in the inner city, the Deutsche Bahn is building a second core line between the stations Laim and Leuchtenbergring. Here, the joint venture VE 41 comprised of Implenia and Hochtief, is carrying out slurry wall work using Liebherr equipment.

High demands

The challenges lie in the large dimensions of the slurry walls and the extremely confined space on the construction site. Due to the historical buildings in the immediate surroundings, an application with low vibration is necessary for the installation of the slurry walls. At the same time, it must also meet the high demands for compactness and verticality. The contractor found the correct equipment in the brand-new Liebherr slurry wall cutter type LSC 8-18 L.

The cutter’s high weight, high cutter frame and low centre of gravity provide the optimum basis to achieve the necessary verticality. Maximum process safety is achieved through the full integration of the verticality measurement in the Liebherr control system. Furthermore, 12 independently controllable steering flaps can correct the cutting direction should any possible deviations occur. The actual position of the flaps is displayed in real time on the monitor in the operator’s cab. In order to deal with the confined spaces of urban construction sites, the cutter can be positioned over the bite using a continuous hydraulic turning device.

The new equipment from Liebherr cuts its way through 33 cubic metres of soil per hour and requires 8 hours for a primary trench. A total of 108 trenches measuring 1500 x 3200 millimetres with 30 centimetres of overlap must be installed on the construction site in Munich.

In addition to the cutter, the hydraulic slurry wall grab, type HSG 5-18, is in operation. It is also fitted with verticality measurement and a turning device for the frame and is mainly used for the initial excavation of the trenches.

Complete package

The carrier machine for both the grab and the cutter is a HS 8130 duty cycle crawler crane. Its excellent stability in combination with the large winches make the HS 8130 an efficient basis for such heavy equipment.

The joint venture is using the separation plant SPC 600 C, which Liebherr offers as part of a complete package for slurry wall applications. The package also includes grab, cutter and duty cycle crawler crane. The plant can process up to 600 cubic metres support fluid including excavation material per hour. In addition to the two duty cycle crawler cranes with slurry wall cutter and grab respectively, the drilling rigs type LB 24 and LB 44 are also working on the cramped site for the expansion of the suburban line. Further, the crawler crane type LR 1250 lifts the reinforcement cages into place, each of which weighs up to 55 tons and is 55 metres high.