Pb^(2+)、Zn^(2+)、Cu^(2+)重金属污染土力学特性及本构关系室内实验研究

Experimental Study on Mechanical Properties and Constitutive Relationship of Soils Contaminated with Heavy Metals(Pb^(2+)、Zn^(2+)、Cu^(2+))

针对重金属(Pb^(2+)、Zn^(2+)、Cu^(2+))污染土孔隙比高、压缩性大、抗剪强度低、承载力差等原因导致的地基强度低、变形大和不均匀沉降等问题。采用室内实验方法对重金属污染土力学特性和本构关系进行了研究。实验表明:与未污染的原状土相比,重塑土的黏聚力与内摩擦角均显著降低;在相同围压下,随着污染土中重金属含量的增加,污染土的峰值强度逐渐降低;污染土中重金属含量对土体的压缩性有显著影响,含量越高、压缩性越强。基于Mastsuoka-Nakai准则与Mises流动法则,给出了考虑多种重金属影响的污染土的本构关系式。

The soil contaminated with heavy metals（Pb^2＋、Zn^2＋、Cu^2＋）has the characteristics of high porosity ratio,high compressibility,low shear strength and poor bearing capacity which resulting in low strength,large deformation and inhomogeneous settlementof the foundation.Mechanical properties and constitutive relations of heavy metals contaminated soils are studied by indoor test method.The following conclusions can be drawn.Firstly cohesive force and internal friction angle of the remolded soils are significantly lower than those of the uncontaminated undisturbed soils.Secondly under the same confining pressurewith the increase of heavy metal content in contaminated the peak strength of contaminated soil decreased gradually.Last but not least the content of heavy metals in contaminated soils has a significant effect on the compressibility of soil,the higher the content,the stronger the compressibility.Based on the Matsuoka-Nakai criterion and the Mises flow law the constitutive relation of the contaminated soil considering the influence of multiple heavy metals is given.