German Society for Soil Mechanics

The German Society for Soil Mechanics ( Degebo ) was founded on December 7, 1928 in Berlin to coordinate German research in geotechnical engineering . Today, however, it has de facto merged into the field of foundation engineering and soil mechanics at the Institute for Civil Engineering at the TU Berlin .

Foundation and motivation

It was founded by representatives of government agencies (Reich Ministry of Transport with its waterways department, Reichsbahn, Prussian Ministry of Culture), the construction industry and universities . At that time there were already three respected soil mechanics institutes in Germany:

the Prussian research institute for foundation engineering and hydraulic engineering under Hans-Detlef Krey , which had a soil mechanics laboratory from 1927,
the Bergakademie Freiberg , where there was a soil mechanics laboratory under Franz Kögler since 1924 ,
and the Hanover Research Institute for Foundation Engineering and Hydraulic Engineering from 1927 (later the Franzius Institute) under the Hydraulic Engineering Professor in Hanover Otto Franzius .

One reason for funding soil mechanics research in its own institute was major problems with damage cases (e.g. landslides) and cost overruns due to insufficient knowledge of soil properties in railway construction and canal construction ( Mittelland Canal ), which is why Degebo's main sponsor was initially the railway and waterway administration.

Degebo's new institute building was built in 1929 on today's Straße des 17. Juni in Berlin (only after the war they moved to Jebensstraße). It was assigned to the TU Berlin , but worked largely independently. The 27 founders included Karl von Terzaghi in Vienna (the most respected soil mechanics expert at the time), Otto Franzius, Franz Kögler, Arnold Agatz (professor of foundation engineering and hydraulic engineering at the TU Berlin), August Hertwig (professor of statics and steel construction at the TU Berlin), Wilhelm Loos . The latter was from 1933 and until 1939 managing director of Degebo.

Upswing from 1930

In the 1930s, Degebo experienced a boom as a central research facility for the large-scale buildings planned by the NSDAP on the sandy soil of Berlin (for example for the world capital Germania ), for which suitable foundation measures had to be examined. Not least for this (but also, for example, for questions of compaction in the construction of the Reichsautobahn), Degebo investigated soil dynamics questions ( August Hertwig , Hans Lorenz , Ramspeck). The soil improvement methods investigated included a deep vibrator method from Keller Grundbau (patented 1933) and a method for creating gravel pillars from Franki while compacting the surrounding soil, similar to their Franki pile method. With improved depth vibrators, Keller was able to compact up to 35 m deep in 1939 in tests that were accompanied by Degebo. The results of soil dynamics research were also laboratory methods for determining the loosest and densest storage, which were then common in Germany.

The Berlin building site was also examined by Degebo from 1937 to 1938 with over 1,000 boreholes with an average depth of 25 to 40 m (and 16,000 soil samples) in order to create a precise building map of Berlin.

Degebo was particularly busy in the 1930s with research into the soil compaction of dams and other soil mechanical issues for the construction of the Reichsautobahn. Among other things, they had to train numerous engineers in soil mechanics.

At Degebo, new soil investigation methods were developed, including soil dynamics test methods and a forerunner of the wing probe (for which a patent was granted in 1929, but which was then developed to practical readiness elsewhere after the Second World War ), later in the 1940s also its own (electric) Pressure soundings (1944, R. Hoffmann), in contrast to the parallel Dutch development with a single probe rod. In addition, the settlement behavior, for example with the heavy load body (1940) and test loads, was investigated, the soil pressure and the ground failure behavior. One of the Degebo scientists who were connected to these developments was Heinz Muhs , who headed Degebo after the war. Terzaghi students like Leo Rendulic (who continued his Viennese triaxial tests here, which had underpinned Terzaghi's theory of effective tensions) and Leo Casagrande (founder of the soil mechanics laboratory at the TU Berlin and significantly involved as a foundation builder in the German motorway construction) worked here. Triaxial devices developed by Arthur Casagrande , who also worked at Degebo from 1933, were purchased and Terzaghi himself, for example, was in Berlin for longer stays in 1935. The first forerunners of the DIN standards for geotechnical engineering were also published at Degebo (for soil sampling in 1928, test loads in 1929, soil description in 1929, 1934 permissible load on the subsoil and pile foundations , which was the forerunner to DIN 1054 , and subsoil investigation in 1935). After the war, this work went to the German Geotechnical Society (DGGT), which was founded in 1950 .

After the Second World War

Even after the war, Degebo's research continued, for example into ground failure (the test results obtained for this purpose have become particularly well known), settlement studies and soil investigation methods. Here the heavy-duty body (mushroom) from the war time proved to be useful for the extensive ground failure tests, because thanks to its mushroom shape it was ideally suited as a counterweight for the soil pressures to be applied. The ground failure and load-bearing capacity tests for shallow foundations also had a practical motivation in Berlin, as numerous old foundations that were difficult to assess had to be increased as part of the reconstruction. The investigations into pressure probes were also continued. Degebo's findings were also often incorporated into the DIN standards. Muhs' successor as director in the 1970s and 1980s was Klaus Weiß .

Today Degebo has practically merged in the field of foundation engineering and soil mechanics at the Institute for Civil Engineering at TU Berlin .

literature

Klaus Weiß: 50 years of the German Research Society for Soil Mechanics (DEGEBO) , announcements from the German Research Society for Soil Mechanics at the Technical University of Berlin, issue 33, 1978.

Heinz Muhs and others: Bautechnik-Archiv, No. 3, 1949 for the 20th anniversary of Degebo.

Web links

Individual evidence

^ A speech by the Reichsbahnrat Ofen in 1927, who was also on the board of Degebo, was influential.
↑ From 1935 with Degebo. He died in the summer of 1945
↑ But also some deep boreholes, two of which even went to 420 m and 526 m
↑ Hoffmann was the managing director of Degebo from 1939 to 1945. He died in a Soviet camp in 1946.
↑ 1940 in the second edition
↑ Guidelines for structural soil investigations

[1] A speech by the Reichsbahnrat Ofen in 1927, who was also on the board of Degebo, was influential.

[2] From 1935 with Degebo. He died in the summer of 1945

[3] But also some deep boreholes, two of which even went to 420 m and 526 m

[4] Hoffmann was the managing director of Degebo from 1939 to 1945. He died in a Soviet camp in 1946.

[5] 1940 in the second edition

[6] Guidelines for structural soil investigations