Effects of barrier deformability on load reduction and energy dissipation of granular flow impact

Autor: C. Wang, Charles Wang Wai Ng, Sunil Poudyal, Clarence Edward Choi, W. A. R. K. De Silva
Rok vydání: 2020
Předmět:
Zdroj: Computers and Geotechnics. 121:103445
ISSN: 0266-352X
DOI: 10.1016/j.compgeo.2020.103445
Popis: Granular flows, such as debris flows, are commonly arrested by using deformable barriers, but their designs rely heavily on empiricism. The fundamental impact mechanisms between a granular flow and a deformable barrier have yet to be elucidated. Thus, estimating the impact load on deformable barriers remains a key scientific and engineering challenge. In this paper, the material point method (MPM), with the Drucker-Prager yield criterion associated with a linear elastic model is calibrated against physical model tests. The effects of barrier deformability on the impact force induced by a granular flow are examined. For simplicity, a vertical and deformable cantilever barrier with different flexural rigidity is simulated. The dissipation of energy of a frictional granular assembly subjected to shear is considered in the simulation. A threshold 3EI/H3norm = 6.3 × 10−5 (normalized by the stiffness of a typical 1-m thick reinforced concrete cantilever barrier) is identified in this study to demarcate between rigid and deformable barriers. A maximum deformation of only 3% of the total barrier height and corresponding reduced relative velocity are enough to attenuate the peak impact load by 40% compared to a rigid barrier. Around 85% of the dissipated energy occurs during the pile-up process, the interaction between the incoming flow and deposited material along the slip interface is effective in dissipating flow kinetic energy.
Databáze: OpenAIRE
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