Influence of direction and rate of removal of confining gate in DEM based granular column simulations mimicking dry granular flows

¹ Indian Institute of Technology Guwahati, India
² Indian Institute of Technology Mandi, India

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Published online: 1 December 2025

Abstract

Dry granular flows exhibit varied complex attributes based on the failure characteristics of natural slopes. However, for simplistic understanding of these flows, lab scale granular column collapse experiments are being widely followed, and while conducting the numerical simulation of the same, an instantaneous collapse of the whole granular mass resembling a dam break problem is usually considered. This differs from the real field scenarios, where flow either commences from the top or from the vicinity of the toe of slopes; and the failure of the slope is not instantaneous, but progressive or rate dependent. Thus, releasing the confining gate of granular column at a certain rate in upward and downward directions may simulate different failure mechanisms yielding greater insights for flow behaviour and depositional morphology of the dry granular flows. In this study, the influence of direction and rate of removal of confining gate has been examined for dry granular flows emanating from the collapse of granular column by implementing 3D – Discrete Element Method (DEM). Three different rates of gate removal, i.e., 0.05, 0.25 and 0.50 m/s have been considered for both upward and downward directions for different aspect ratios of the granular column and the results have been analysed.