重金属离子污染粉砂土力学性能试验研究

Experimental Study on Mechanical Properties of Silty Sand Pollution by Heavy Metal Ions

为了探究重金属离子对粉砂土力学性能的影响,配制不同重金属离子含量的污染土试样,进行无侧限抗压试验、直剪试验和X射线衍射分析试验。试验表明:铬离子渗入会增大土体抗压强度,而铜离子加入会导致土体抗压强度减小;铬离子和铜离子掺入量的增加均会引起土体抗剪强度下降;借助X射线衍射试验发现,铜、铬离子的渗入会改变土体内SiO2化合物的含量及形态。综合分析表明,铬离子、铜离子会改变土中SiO2的含量,从而影响土的力学性能。

To study the effects of heavy metal ions on the mechanical properties of silty sand, types of samples contaminated with different contents of metal ions were prepared. The unconfined compressive strength tests, direct shear tests, and X-ray diffraction tests were performed. Results show that the compression strength of soil would rise with the chromium ion permeating;however, the index decreases with the copper ion mixing. The shear strength of soil can reduce with the increasing of copper or chromium ions contents. Based on X-ray diffraction tests, the copper or chromium ions can change the content and compound morphology of SiO2 in the soil. The comprehensive analysis show that the copper and chromium ions could change the content of SiO2, thus affecting the mechanical properties of silty sand.