The supporting effect of bentonite suspension was already in the 19th century by drilling engineers and by the miners in 1893 (Honigmann’sches Schachtbohrverfahren) used. Patents were awarded for diaphragm walls, which are made with the help of bentonite suspension Brandt 1912 and Ranney 1936 first. The latter developed machines for the production of continuous ground slots. Until the beginning of the 1950s years of this century but was the slot wall construction by the patents by Professor Dr.-Ing. Enver, Graz (drill pile walls manufactured for unverrohrt) and Professor Dr.-Ing. H. Lorenz, Berlin (the diaphragm wall in the shape of today’s standard) known and since then executed on a large scale.
The diaphragm walls find their application primarily as a construction pit walls in large, very deep excavation pits for multi roofed buildings, as well as for urban tunnels of public transport or road tunnel. In the Federal Republic of Germany, the slot wall construction is as follows:
-DIN 4127 (earthwork and foundation engineering): “Slot wall clays for supporting fluids, requirements, testing, delivery, quality monitoring.” Issue of August, 1986.
-DIN 4126: “site-mixed concrete – diaphragm walls – construction and performance.” Issue of August, 1986.
-DIN 18313: “slot wall to work with supporting liquids.” Edition 1984.
-EAU and EAB information