Photoelastic experiments on force chain evolution in granular materials under bilateral flowing conditions

Abstract

In order to make a better understanding of force transition and stability mechanism of granular materials in meso-scale, a series of photoelastic experiments particle flowing are observed. Under varies loading and flowing conditions, the particle flowing are observed. Under varies loading and flowing conditions, the mesoscopic structures of force chain are observed within granular media. It shows that arching phenomena can be recognized near the flowing site as particle flowing. When particles flow through the bottom gate, a parabolic arch formed by strong force chains grows; and a semi-arch deviates, when particles flow through a lateral gate. The arching effect shield stress from transferring to the flowing region. As a result, a great number of weak force chains concentrate around the flowing spot. And the arch changes in a periodic pattern and the force chain network is updated continually as particle flowing continues. The development trend of force chains as a whole depends on particle flowing as well as loading directions. Compared with the vertical growth of force chains under a tangential load, they extend mainly along a horizontal trend when a tangential load is applied to the model.