The exact prediction of the forces that act on the vertical walls of silo is major problem when it comes to the question of design of these structures. In order to measure the forces acting on the bottom and vertical walls of the silo, the vertical wall and the bottom of a pilot vertical flat-bottom cylindrical silo was instrumented through load cells and pressure cells. The cell readings were performed by automatic data acquisition during loading and unloading of dry sand. The silo was concentrically loaded and concentric and eccentrically unloaded from two eccentricities. The experiment took place during the period from January to April 2008 at the Environment and Rural Construction Laboratory of Federal University of Campina Grande, Paraíba. The experimental values were compared with the standards Eurocode 1, ISO 11697, AS 3774 and DIN 1055. It can be concluded that theoretical values of vertical force were overestimated when compared with experimental results for majority of unloading methods. For friction forces on silo walls, the values from standards were compatible with the experimental results.
storage structures; instrumentation; loading; unloading
