of the Marienplatz underground station in Munich

During the extension of Munich’s busiest public transport hub, the Marienplatz underground station, two additional tunnel tubes were built to make the underground platforms twice as large. This was to disentangle passenger flow between the city underground and the suburban commuter railway. The old and new extension tunnels are now linked by a total of 22 breakthroughs. The complex construction process took place while the underground continued to fully operate. The crucial challenge was to freeze a sand aquifer located directly above the new platform tubes. Since Munich’s historic Town Hall was located above the two tunnels, it was impossible to drain the tubes with vertical extracting wells from above ground.
Using a compressed-air cowl shield, approximately 100-metre long pilot tunnels were driven from two 30-metre deep ertical shafts. From inside the pilot tunnels, the ground was frozen with calcium chloride brine cooled down to -40° C. Protected by the frozen ice-caps, the two platform tubes, almost 100 metres long, were constructed using reinforcement and sprayed concrete, in compliance with mining safety standards. The freezing plant was operated intermittently and adjusted when necessary to meet specific requirements during the construction phase. As a consequence, the extent of deformation remained well belowthe tolerance limit specified by the Munich Underground Department.



Frankfurter Ring 105
D-80807 Munich, Germany
Phone + 49 89 350607-11327
Fax + 49 89 350607-25
This email address is being protected from spambots. You need JavaScript enabled to view it.