冻结砂土力学性质的离散元模拟

Simulation of mechanical behavior for frozen sand clay by discrete element method

基于离散单元法颗粒流理论,土体颗粒单元间采用接触黏结模型中来考虑冻土中冰的胶结作用,建立了冻结砂土的颗粒流模型。通过改变计算模型中颗粒单元的参数,模拟了在不同冻结温度以及不同围压下冻结砂土的宏观力学性质,并与冻结砂土的室内试验结果进行了比较,结果表明:颗粒流方法可以较好地模拟冻结砂土的应力-应变关系以及剪切带的发展变化过程,颗粒流细观参数对温度具有显著的依赖性。研究结果对离散单元法在特殊土中的应用具有一定的理论和应用价值。

Based on the discrete element method （DEM）, the model of particle flow for frozen sand clay has been established, the contact-bond model among balls is adopted in the simulation test. According to this model, the contact bond strength was employed to simulate the cementation of ice in the frozen sand clay. Comparison between the results of numerical simulations and laboratory tests under different temperature and confining pressure, the results shows good agreement between them. It is similar to the macro properties of frozen sand clay that the parameters of particle elements have the property of evident temperature-dependent. The results are valuable for developing the applicability of the DEM to analysis of special soil.