Investigation of Measuring Wall Friction on a Large Scale Wall Friction Tester and the Jenike Direct Shear Tester
The interaction of a granular material with boundary materials is one of the most important factors to consider when designing mass flow hoppers, chutes, feeders and other equipment where flow is expected to occur. Numerous properties of a bulk material and wall surface influence the measurement of wall friction angles (e.g. particle size and distribution, particle shape, particle and boundary asperities and moisture content) which can be difficult to thoroughly investigate on a standard Jenike direct shear tester. Often the Jenike direct shear tester is limited to small particle sizes, wall sample materials, shear rates and displacements.This paper presents the design and commissioning of a new large scale wall friction tester (LSWFT) to measure the wall friction angles of dry and wet bulk materials with a wide particle size distribution using a large shear cell. Factors which are examined on the LSWFT include particle size, moisture content, wall sample material conditions (i.e. effects of joints and edges between tiled materials) and shear cell size to improve the understanding of granular material interaction withboundaries to enhance infrastructure performance. The wall yield loci and kinematic angles of wall friction measured from the LSWFT are compared to the Jenike direct shear tester to examine the difference between the two measuring techniques and evaluate the performance of the LSWFT. The results presented in this paper are preliminary and are not intended to show any particle or shear cell scaling effects but to rather demonstrate the potential usefulness of the LSWFT and limitations of the Jenike tester.
Grima, A. P., Mills, B. P. Wypych, P. W. (2010). Investigation of Measuring Wall Friction on a Large Scale Wall Friction Tester and the Jenike Direct Shear Tester. 3rd International conference exhibition BulkSolids Europe 2010 (pp. 1-14). Wuerzburg, Germany: Gerd Kielburger.