室外大型尾矿库物理模型管涌溃坝演化过程研究

A Study on the Evolution Process of Piping Failure in Large Outdoor Tailings Ponds Physical Model

人工或天然形成的大坝溃决通常引起巨大的灾难,坝体溃决过程预测是开展溃坝灾害预防预警工作的首先前提,吸引了很多学者进行了深入研究.然而已有溃坝方面的研究成果主要是针对水库大坝建立的,尾矿坝是由尾矿浆逐层分选沉积形成的,因此在筑坝材料、坝体结构、溃坝因素、水源补给等多个方面,水库大坝和尾矿坝存在较大的差异.目前关于尾矿库溃坝的研究主要集中在溃坝因素分析和坝体稳定性评价方面,针对溃坝流量过程预测以及溃坝模型的研究尚处于起始阶段.基于以上考虑,本项目拟通过开展大型尾矿库溃坝物理模型试验,揭示溃坝溃口扩展特征.

A refinement method is proposed to solve the difference in the macroscopic elasticity and the interpenetration in interface area between different particle-size areas in the DEM.In simulations of 3D DEM large-scale problems,small balls are used in the near field core area to simulate the real soil,while the far field boundary regions are filled with larger balls.In addition,a mixed area is set between different particle-size areas with the same relative density.The number of particles in the model can be reduced enormously,which improves largely the calculation efficiency.For scaling particle systems,the scale relationship is established on the static condition by the identical macro elasticity of uniform granules.The relationship satisfies the consistency of stress,strain and strain energy.The results of a series of triaxial test simulations verify the uniformity of macro elasticity.A method to generate a certain density mixture with two different particle sizes is proposed.The results of DEM simulations illustrate that the deformation property of mixed area is consistent with that of the uniform particles.Finally,the results of cone penetration test simulations show that the proposed method is effective.This study may provide a new approach to the application of 3D discrete element modelling in the large-scale geotechnical engineering.