Print Email Facebook Twitter The adherence of clay to steel surfaces Title The adherence of clay to steel surfaces Author Zimnik, André R. (HAM Dredging) Van Baalen, Lennart R. (Student TU Delft) Verhoef, P.N.W. (TU Delft Geo-engineering) Ngan-Tillard, D.J.M. (TU Delft Geo-engineering) Date 2018-01-01 Abstract Recently the first full face tunnel boring machines were used in the Netherlands. Several problems have been encountered in tunnelling projects in the Dutch soft soils. One was the adherence of stiff clays to the TBM cutting wheel, mixing chamber and the pipelines, which transport the clay from the front. Adherence of clay can be described in terms of adhesion and adhesive friction. Parameters which influence these two factors are on one hand the mineralogy, texture, the (over)-consolidation ratio and composition of the clay and on the other hand the type of steel and the textural state and condition of the steel surface. To study the adherence of clay, two types of clays were tested. Tests have been performed on Speswhite, which consists mostly of kaolinite and on Boom clay, which is a mixture of quartz, illite and kaolinite. Samples were prepared from clay powders. The adherence behaviour of clay was investigated by measuring the shear stress required to shear the clay over a steel surface in a direct shearbox. Results show a great influence of the steel roughness, contact time and mineral type. This is in accordance with practical experience and previous literature. The shearbox test gives a good quantitative impression of the adhesive shear strength, however it is expected that other devices like the simple shearbox and the ring shearbox are better suited to study the parameter variation during the tests. To reference this document use: http://resolver.tudelft.nl/uuid:fd8a407b-f7ea-492b-9866-2dc2b9a251bb Publisher International Society for Rock Mechanics Source ISRM International Symposium 2000, IS 2000 Event ISRM International Symposium 2000, IS 2000, 2000-11-19 → 2000-11-24, Lancaster, USA, Melbourne, Australia Part of collection Institutional Repository Document type conference paper Rights © 2018 André R. Zimnik, Lennart R. Van Baalen, P.N.W. Verhoef, D.J.M. Ngan-Tillard Files PDF ISRM_IS_2000_598.pdf 141.83 KB Close viewer /islandora/object/uuid:fd8a407b-f7ea-492b-9866-2dc2b9a251bb/datastream/OBJ/view