冻融循环作用对露天矿排土场土料土水特征的影响

为了研究冻融循环条件下排土场土料的非饱和土水特征，选取元宝山露天矿内排土场土料为对象，研究不同体积含水率状态下土料在经历不同冻融循环次数后的基质吸力与宏细观结构的变化规律。结果表明:经历相同冻融循环次数时，基质吸力随含水率的减小而增加，且增加的幅度逐渐增大，土水特征曲线可划分为敏感阶段、亚敏感阶段和不敏感阶段；随着冻融次数的增加，土水特征曲线的曲率呈先增大后趋于稳定的规律，且基质吸力对冻融循环次数增加的敏感程度逐渐降低；冻融循环作用破坏土颗粒的均匀程度，且初次冻融循环影响最为显著；Van-Genuchten模型能较好地预测土料土水的特征曲线。因此，矿山排土过程中应重视冻融循环作用对排土场边坡稳定性的影响。 

Influence of the freezing-thawing cycles on soil-water characteristics of soil in open-pit mine dumping sites

In order to study the unsaturated soil-water characteristics of soil under freezing-thawing cycles, the soil in Yuanbaoshan open-pit mine dumping site was selected as the research object. The variation of matrix suction and structure of soil under different water content after different freezing-thawing cycles was studied. The results show that during the same freezing-thawing cycles, the matrix suction increases with the decrease of water content, and the range increases gradually. The soil-water characteristic curve can be divided into sensitive stage, sub-sensitive stage and insensitive stage. With the increase of freezing-thawing cycles, the curvature of soil-water characteristic curve increases first and then tends to be stable, and the sensitivity of matrix suction to the increase of freezing-thawing cycles decreases gradually. Freezing-thawing cycles destroy the uniformity of soil particles, and the influence of initial freezing-thawing cycles is the most significant. Van-Genuchten model can better predict the soil-water characteristic curve of soil. Therefore, the influence of freezing-thawing cycles on the stability of dump slope should be emphasized in the process of mine dumping.