Patterns of wall pressure on filling a square planform steel silo

This paper reports the filling pressures measured in a rectangular planform silo with flexible walls. Many experiments were conducted on a pilot-scale square unstiffened steel silo with a pyramidal hopper. The stress state in the solid stored in the silo was thoroughly investigated during filling using both wall pressure cells and free field pressure cells. The results show that the pressure distribution at any given depth at the end of filling may be far from uniform, though most existing silo pressure theories and design codes assume uniformity in any horizontal plane. High pressures were found to develop in the corners of the silo, with corresponding lower pressures at the centre of the walls. An explanation is offered for the observed pressure pattern and a design proposal is made.