重金属污染土强度特性试验研究

通过将重金属冶炼企业的尾矿库、废料堆填区采取重金属尾矿样品，与无污染净土进行混合，制作不同重金属污染物含量的土样，进行物化分析、直接剪切试验与无侧限抗压强度等试验，研究了重金属污染物的不同含量对土体强度特性的影响。试验结果表明，重金属污染物对土体强度特性有较大影响，随着污染物浓度的增加，其粘聚力增大，则内摩擦角呈降低趋势。在同一含水量的情况下，随着重金属污染土含量的增加，其强度总体上有减小的趋势。强度随着重金属污染土掺入比的增加，其降低量也逐渐增加，降低量约为35％～60％。重金属污染物通过土颗粒间双电层与水膜厚度与表面性质，打破颗粒间的电离平衡，从而改变土体的强度性质。

Experimental Analysis of the Strength Properties of the Heavy Metal Contaminanted Soil

The samples contaminated by heavy metal were taken from tailing pond and landfill site of wastes The different heavy metal contamination samples with different incorporation ratio are respectively mixed with the undisturbed soil . The content analysis of heavy metal , direct shear test and unconfined compression strength test are carried out in order to study the strength properties of the heavy metal pollution .T he results of test and analysis show that ：the heavy metal pollution has a very strong impact on the strength properties of soil .With the increase of concentration of heavy metal pollutants i ,c‐value gradually increased and φvalue decreased .Under the same water content ,the unconfined compression strength is reduced with the increase of heavy metal content .The strength will decrease by approximately 35% ~60% .The characteristics of the diffuse double layer and the thickness of the water film between the soil particles will change when the heavy metal contaminants the soil ,the balance relationship between cationic and anionic on the soil surface will also be broken . Therefore , the strength properties of the contaminanted soil will change .