Cu(Ⅱ)对重塑黄土抗剪强度和电阻率的影响

Study on Shear Strength and Electrical Resistivity of Remolded Loess Contaminated by Cu^(2+)

为研究Cu2+含量不同对重塑土的抗剪强度影响以及剪切过程中电阻率变化,进行了室内直剪试验。制取含量为0mg/kg、5 mg/kg、50 mg/kg、500 mg/kg、5 000 mg/kg的五种Cu2+污染重塑土,对其进行直剪试验和电阻率试验,最后处理并分析数据。结果表明:随Cu2+含量增加,电阻率减小,且电阻率浮动变小,电阻率随剪切位移增大呈减小的趋势,含量500 mg/kg时的电阻率浮动小,规律明显;Cu2+污染土剪应力随剪切位移增大不断增加,没有明显的屈服点;Cu2+含量小于5 mg/kg时,Cu2+污染土抗剪强度随Cu2+含量增加而增加,Cu2+含量大于500 mg/kg时,Cu2+污染土抗剪强度随Cu2+含量增加而减小;同一含量下的污染土在不同垂直压力下的抗剪强度与电阻率呈负相关,Cu2+含量越大抗剪强度变化对电阻率越不敏感;定义了电阻率角、初始电阻率,电阻率角反映电阻率对土体结构变化的敏感程度,初始电阻率为土体在没有垂直压力作用下时的电阻率。

To study the shear strength and electrical resistivity of remolded loess contaminated by Cu^2＋in different quantity,laboratory tests were conducted. Remolded loess samples contaminated by Cu^2＋was prepared in the quantity of 0 mg / kg、5 mg / kg、50 mg / kg、500 mg / kg、5000 mg / kg,then tested the electrical resistivity and shear strength,handled and analyzed the dates. The results showed that： with Cu^2＋increasing,the electrical resistivity decreased,and floated smaller,the principle was better and the floating was smaller when Cu^2＋was 500 mg / kg;with the displacement increasing,the shear strength increased all through; when the quantity of Cu^2＋was smaller than 5 mg / kg,the shear strength increased with the Cu^2＋increasing,when the quantity of Cu^2＋was bigger than500 mg / kg,the shear strength decreased with the Cu^2＋increasing,the larger the electrical resistivity,the smaller the shear strength; with Cu^2＋increasing,the shear strength was less sensitive to electrical resistivity; defined the electrical resistivity grade and the original electrical resistivity of remolded loess,the larger the electrical resistivity it can reflect the changes of the soil＇s structure better,the original electrical resistivity stand for the electrical resistivity when there was no press on the soil.