Grain silos tests under shaking table loads

This paper reports describes a series of shaking table tests performed at the EQUALS lab of Bristol University in the framework of the SERIES FP7 project. The experimental test campaign was devoted to the evaluation of the effective behavior of flat-bottom silos filled of grain up to a certain height under base dynamic excitation, and to the experimental verification of the results obtained in a previous analytical research work by the authors. The analyses are developed by simulating the earthquake ground motion with time constant vertical and horizontal accelerations and are carried out by means of simple dynamic equilibrium equations that take into consideration the specific mutual actions developing in the ensiled grain. Different series of tests have been performed with different heights of the ensiled material to simulate a silo more or less squat. In this paper, the silo specimen and the test instrumentation are described, and the test program and the results are presented. Strong qualitative indications are obtained which basically confirm that the wall-grain friction coefficient plays an important role in the actions at the base of the silo walls.