Experimental Study Of Effects Of Heavy Metal Pollution On Engineering Characteristics Of Cement Solidified Soil

Heavy metal pollution can cause deterioration of performance of cement soil engineering and lead project accidents. As an important means of dealing with heavy metal pollution, Cement Solidification method will pose a threat to the surrounding environment which may cause secondary pollution. Therefore, taking heavy metals lead, copper as the typical ingredients of soil pollution. Then, soil is formed different pollution levels with the heavy metal. And then soil pollution is solidified by cement. By laboratory tests, having a study on the electrical resistivity characteristics, strength characteristics, leaching toxicity and permeability of cement soil, which would be effected by heavy metal ions. Concluded that:Firstly, having an electrical resistivity test on cement soil samples under five different ages and seven polluted levels, which contaminated by Pb and Cu. Concluded that: When the electrical resistivity characteristics of cement solidification contaminated soil were analyzed, current frequency range of 50 kHz to 1 MHz was recommended. Because, in this frequency range, electrical resistivity data is relatively stable. Heavy metal ions have an impact on electrical resistivity of cemented soil. On the whole, the more serious pollution heavy metal, the smaller electrical resistivity of cemented soil.Second, having an unconfined compressive strength test on cement soil samples under five different ages and seven polluted levels, which contaminated by Pb and Cu. Concluded that: Heavy metal ions have an impact on strength of cemented soil. It causes strength of cement solidification soil increase or decrease. Electrical resistivity and unconfined compressive strength have a functional relationship.Third, having a leaching toxicity test on cement soil samples under 28 d and 60 d ages, which contaminated by Cu. Concluded that: When Cu ions content ranges from 0-2500 mg/kg, solidified soil, with 15% of the cement content, can meet the relevant waste discharge standards. Overall, Cu ions content in leaching solution have a relationship with degree of contamination. When Cu ions content ranges from 1000 mg/kg to 2500 mg/kg, Solidifying and stabilizing effect will be significant deterioration.Fourth,having a permeability test on cement soil samples under five different ages and seven polluted levels, which contaminated by Cu. Concluded that: Cu ions have an impact on permeability coefficient of cemented soil. With the increased of Cu ions content, Permeability coefficient increases and then decreases at first, after increase and in the end has a small decrease. When Cu ions content is 1000 mg/kg, permeability coefficient is the largest. When Cu ions content is excessive, impermeability of cement soil will be deteriorated. So it should be considered in the project. Impermeability coefficient of cement soil decreases with electrical resistivity increases. At the same time, impermeability coefficient of cement soil decreases with strength increases.