基于电阻率表征的固化镉污染土的力学特性

Mechanical Characteristics of Solidified Chromium Contaminated Soil on the Basis of Resistivity Representations

【目的】探寻固化重金属污染土的力学性能的间接测量评估方法。【方法】采用电阻率-无侧限抗压强度联合测试方法,研究了固废固化重金属镉污染土试块的力学和电学特性。【结果】结果表明:赤泥-电石渣-磷石膏固化镉污染土体具有较高的强度,其峰值应力和破坏应变均随龄期增大而提高;固化土具有稳定的强度-电阻率变化规律,二者具有良好的线性关系;通过分析应力-应变-动态电阻率曲线,发现动态电阻率与应变具有良好的幂函数关系,将动态电阻率替代应变软化模型中的应变,建立了力学的电学表征模型,经对比验证,吻合度较高,表明用动态电阻率变化值表征固化土受力和变形状态具有较高的可信度。

【Purposes】 This study is conducted to explore the indirect measurement method of mechanical properties of solidified heavy metal contaminated soil.【Methods】 The combined resistivity-unconfined compression test method was carried out to investigate the strength and electrical properties of solid waste solidified contaminated soil.【Findings】 The results show that the red mud-carbide slag-phosphogypsum solidified contaminated soil has higher strength,in which,both peak stress and failure strain increase with the increase of curing age.The solidified soil also exhibits a stable change law between its strength and resistivity.There is a stable variation law between the strength and resistivity of the solidified soil,which shows a good linear relationship.A power function relationship between strain and dynamic resistivity is also observed through stress-strain-dynamic resistivity curve analysis.An electrical characterization model of mechanics is established by replacing the strain with dynamic resistivity in the strain softening model.Coincidence degree of the model is high according to comparison and verification,indicating that the dynamic resistivity change value has high reliability to represent the stress and deformation performances of the solidified soil.