论文部分内容阅读
通过在实际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,与代表性净土进行掺和,配制了不同压实度、不同龄期、不同掺和比的重金属污染土样;在各自的最优含水量下,进行击实和直接剪切等物理力学试验,研究重金属污染对土的压实特性与抗剪强度的影响规律。试验表明:1)重金属污染对土体击实特性的影响,金属Mn的影响不大,Pb、Zn、Cd、Cr影响较大,后者表现为随掺和比增大,最优含水量减小,土的最大干密度增大;2)随着重金属污染土体压实度的增大,土的黏聚力C逐渐增大的,内摩擦角φ值逐渐降低,污染土的强度指标明显低于重塑净土的抗剪强度指标;3)重金属污染的作用效应是一个缓慢的过程,随着重金属污染物作用时间的延长,土的黏聚力c值下降,内摩擦角φ值上升;4)随着污染浓度的增加,土的黏聚力c值增大,则φ值呈降低趋势。
The heavy metal tailing samples were taken from the tailings pond and waste landfill site of the actual heavy metal smelting enterprises and blended with representative pure soils to prepare heavy metal contaminated soil samples with different compaction degrees, different ages and different blending ratios. Under the optimal water content, physical and mechanical tests such as compaction and direct shear were carried out to study the influence of heavy metal pollution on soil compaction and shear strength. The results show that: 1) The effect of heavy metal pollution on the compaction characteristics of soil, the effect of metal Mn is not significant, and the effect of Pb, Zn, Cd and Cr is significant. The latter is shown as the increase of mixing ratio and the decrease of the optimum water content The maximum dry density of small soil and soil increased; 2) With the increase of compaction degree of soil polluted by heavy metals, the cohesion C of soil increased gradually, the internal friction angle φ gradually decreased, and the strength index of contaminated soil was obvious Which is lower than that of remolded pure soil. 3) The effect of heavy metal pollution is a slow process. With the extension of the action time of heavy metal pollutants, the c cohesion value of soil decreases and the internal friction angle φ increases. 4) With the increase of pollution concentration, the value of c cohesion increases, then the value of φ decreases.