ABSTRACT
Conditioning agents are used to prevent EPB-TBMs from clogging in fine-grained soils. Due to a wide range in available conditioning agents available and the varying properties and composition of the subsoil, laboratory tests are conducted to determine the clogging potential of a certain soil and subsequently choose a suitable conditioning agent for the specific project. For this purpose, a testing device ATUR was developed in 2018 during a cooperation of Queen’s University, Canada and Ruhr-University Bochum (RUB), Germany (Oliveira, 2018). Recently, BabEng GmbH and RUB have improved the test principles which lead to the construction of ATUR 2.0. This paper describes the fundamentals of clogging mechanism based on standard soil mechanical parameters as well as the physical principle of the testing device. The results of a extensive test series are compared to proven and trusted theories and demonstrate the application area throughout challenging ground conditions beyond standard application ranges.
