The paper records some of the results and observations from a pilot scale plane-flow silo with a variable geometry hopper and a fully width slot outlet. The original objectives were simply to study the shape of arches and their failure mechanisms under a range of conditions. However, the behaviour of arches did not conform to the conventional assumptions and neither did other silo behaviour. The paper contains a summary of the main findings of this work, but concentrates on the arches formed

more »

... er mass-flow and non-mass-flow geometries for the filling condition.