铝土尾矿泡沫轻质土单轴抗压力学特性及唯象本构模型
Uniaxial Compressive Mechanical Properties and Phenomenological Constitutive Model of Foamed Mixture Lightweight Soil with Bauxite Tailings
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摘要: 铝土尾矿泥是一种常见的工业废弃物,为了更好地利用铝土尾矿泥,减少其对环境的污染,将铝土尾矿泥掺入泡沫轻质土中制备新型铝土尾矿泡沫轻质土,研究了铝土尾矿泥掺量对铝土尾矿泡沫轻质土抗压强度及破坏模式的影响,并基于两参数Weibull分布函数,提出适用于铝土尾矿泡沫轻质土材料的一维受压损伤本构模型.研究结果表明,铝土尾矿泡沫轻质土的无侧限抗压强度随着铝土尾矿泥掺量的增加呈指数型减小,7d无侧限抗压强度可达到28d无侧限抗压强度的83%;铝土尾矿泡沫轻质土的名义应力-应变曲线在单轴受压作用下主要包括弹塑性阶段和破坏平台阶段,在单轴受压破坏之后存在应变软化和应变硬化行为,具备良好的缓冲性能;根据Weibull分布函数和Avalle模型,研究了铝土尾矿泡沫轻质土材料一维受压损伤唯象本构模型,建立了模型参数与铝土尾矿泥掺量的关系式,为铝土尾矿泥在泡沫轻质土中的应用提供参考.Abstract: Bauxite tailings(BTs) is a common industrial waste.In order to make better use of BTs and reduce its pollution to the environment,a new type of foamed mixture lightweight soil(FMLS) with BTs was fabricated.The influence of BTs content on the compressive strength and failure mode of FMLS with BTs was studied in this paper.Based on the two-parameter Weibull distribution function,a one-dimensional compression damage constitutive model for FMLS with BTs was proposed.The results show that the unconfined compressive strength of FMLS with BTs decreases exponentially with the increase of BTs content.The 7d unconfined compressive strength up to 83% of the 28d unconfined compressive strength.Nominal stress-strain curves of the FMLS with BTs under uniaxial compression includes elastic-plastic stage and failure platform stage.FMLS with BTs exhibits strain-softening and strain hardening behavior after uniaxial compression failure,showing good cushioning properties.According to the Weibull distribution function and Avalle model,a one-dimensional compression damage phenomenological constitutive model for FMLS with BTs is investigated.The relationship between the model parameters and the BTs content is established,which provide a reference for the application of BTs in FMLS.