Bentonites have good application in solid walls, waterproof materials, and landfill cushions, but the cushions of landfills in seasonal frozen regions are susceptible to the effects of freeze–thaw cycles, overhead dynamic loads, and landfill leachate, which can lead to strength change and structural instability. In this paper, the cations in bentonite were exchanged by electrochemical method, and then a series of low-temperature triaxial tests were carried out on the original and modified bentonite. The study evaluated the dynamic characteristics of the different exchange ions under the factors of confining pressures, freeze–thaw cycles, and loading frequencies. The results showed that (1) the electrochemical cation exchange method can effectively replace Na⁺ in the Na⁺-bentonite; (2) under cyclic loading, with increasing shear strain, the shear modulus ratio decreased, and the damping ratio was gradually increased; (3) the dynamic shear modulus ratio increases with the increase of confining pressures and frequencies, and the number of freeze–thaw cycles had little effect on the dynamic shear modulus ratio; and (4) the dynamic parameters of modified bentonite were less affected by external factors and soil’s structure were more stable.

膨润土在实心墙体、防水材料、垃圾填埋场垫层等方面有很好的应用，但季节性冻土区填埋场垫层易受冻融循环、架空动载荷和垃圾渗滤液的影响，导致强度变化，结构不稳定。本文采用电化学方法对膨润土中的阳离子进行交换，然后对原膨润土和改性膨润土进行了一系列低温三轴试验。该研究评估了不同交换离子在围压、冻融循环和加载频率等因素下的动态特性。结果表明：（1）电化学阳离子交换法可以有效取代Na ⁺中的Na ⁺-膨润土；(2)在循环荷载作用下，随着剪切应变的增加，剪切模量比减小，阻尼比逐渐增大；(3) 动剪切模量比随围压和频率的增加而增大，冻融循环次数对动剪切模量比影响不大；(4)改性膨润土的动力参数受外界因素影响较小，土壤结构更稳定。