不同围压下冻结黄土胶结行为的离散元分析

鉴于冻土中冰的胶结作用在冻土力学性质方面的重要作用，在三维离散元法中，采用黏结发生在有限范围内的模型来考虑冰的胶结作用，对不同围压下冻结黄土的胶结行为进行了数值研究。结果表明：数值模拟的应力-应变曲线与试验数据吻和较好；颗粒接触刚度、平行黏结刚度和强度均随着围压增大而线性增大，但摩擦系数随围压增大而减小；力链、位移和孔隙率与围压的响应关系呈现出统一性。同时，也分析了冰胶结作用影响下的冻土细观变化与宏观力学行为之间的响应关系。这对于促进离散元法在冻土领域内的应用具有积极的作用。

Discrete element analysis of cemented behavior of frozen loess under different confining pressures

The cementation of ice makes a significant impact on mechanical properties of the frozen soil,so a bonding model which is effective in a limited range is used to simulate this cementation.Based on three-dimensional discrete element method (DEM) of particle flow code,a numerical research on cemented behavior of frozen loess under different confining pressures is carded out.The results show that simulated stress-strain relationships agree well with experimental data.Particle stiffness,parallel bond stiffness and strength all linearly increase with confining pressures,but friction coefficient shows an opposite tendency.Contact force chains,displacements and porosities exhibit a unity with the response of confining pressures.Meanwhile,the relationship is also analyzed between response of microscopic changes and macroscopic mechanical behavior under the effect of ice cementation.These studies will play an active role in application of DEM to frozen soil field.