金属离子的掺入会明显引发黏性土微观结构变化，改变土体力学行为。探讨了四种常见金属离子（包括一价碱金属离子Na⁺、K⁺和二价重金属离子Pb²⁺、Zn²⁺），重点分析了离子价态、类型和浓度如何影响土壤的微观结构和力学性能。微观结构测试表明，金属离子的掺入降低了颗粒的粒径，增加了黏粒含量，并使结构从层状变为蜂窝状。小孔隙逐渐减少，大孔隙占主导地位，比表面积和孔隙体积减小，而平均孔径增大。阳离子交换容量下降，但表面积阳离子吸附密度增加。一价离子主要通过分散作用影响土体结构，而二价离子则通过凝聚作用改变结构。宏观力学测试表明，金属离子污染在荷载下降低了土体的孔隙率，随着离子浓度的增加，土体的可压缩性增加。受碱金属离子污染的土壤在所有荷载条件下显示出较高的压缩系数，而重金属离子则在较低荷载下引起更高的压缩。相比未受污染的天然土，金属离子污染的黏土在抗剪强度、内摩擦角和凝聚力均有所下降，且随着离子浓度的增加，下降幅度更大。

The incorporation of metal ions is found to significantly trigger microstructural changes in clay, altering its mechanical behavior. Four common metal ions, such as monovalent alkali metal ions (Na⁺, K⁺) and divalent heavy metal ions (Pb²⁺, Zn²⁺) were investigated, focusing on how ion valence, type, and concentration influence soil microstructure and mechanical properties. Microstructural tests were conducted through particle size analysis and structural characterization. Macro-mechanical behavior was evaluated using compression and shear tests. Experimental results show that metal ion incorporation reduces particle size and increases clay content. The soil structure is transformed from layered to honeycomb configuration. Small pores are reduced while large pores become predominant. Specific surface area and pore volume are decreased, whereas average pore size is increased. Cation exchange capacity is reduced, but cation adsorption density per unit surface area is enhanced. Monovalent ions are observed to disperse soil aggregates, while divalent ions are identified to induce coagulation. Metal ion contamination is observed to reduce porosity under loading. Soil compressibility is increased with higher ion concentrations. Alkali metal ion-contaminated clays exhibit higher compression coefficients under all load conditions. Heavy metal ion-contaminated clays demonstrate greater compressibility under lower loads. Compared to fieldstate clay, shear strength parameters (internal friction angle and cohesion) of metal ion-contaminated clay are decreased. These reductions are amplified at elevated ion concentrations.