【摘要】 膨胀土原位膨胀性能受自身含水特性和结构特性等天然状态影响显著，高效精准地判别原位膨胀土膨胀潜能是工程界的重点难题。针对原位膨胀土膨胀性评价问题，采用室内人工配置膨胀土和天然膨胀土作为研究对象，开展低频电法测试及膨胀率试验研究，建立基于低频电法指标的膨胀土无荷膨胀率评价模型。研究结果表明：无荷膨胀率在定干密度情况下随含水率的增加而降低，膨胀土膨胀率受初始状态含水率以及孔隙结构特性影响显著，且最终膨胀率与土颗粒矿物吸水性相关。含水率和干密度的变化也会极大地影响电阻率指标。电阻率指标具有对土体含水情况的高度敏感性，以及对膨胀土矿物颗粒吸水能力的表征性表明，电阻率指标可有效评价原位膨胀土膨胀性能。在此基础上对电阻率、干密度和含水率进行归一化处理，提出了归一化水电综合指标Q的原位膨胀土无荷膨胀率评价模型。结合已有试验数据验证，所提出的原位膨胀土膨胀率电学评价模型具有直接高效的特点，可较好地评价原位膨胀土膨胀潜能。更多还原

【Abstract】 The expansive performance of in-situ expansive soil is significantly influenced by its natural characteristics such as water content and structural properties. Effectively and accurately determining the in-situ expansion potential of expansive soil is a key challenge in engineering. To evaluate the expansiveness of in-situ expansive soil, artificial and natural expansive soils were selected as research subjects. Low-frequency electrical tests and expansion ratio experiments were conducted to establish an evaluation model for the non-loaded expansion ratio of expansive soil based on low-frequency electrical indicators. The research results indicate that the expansion ratio without load decreases as water content increases at a constant dry density. The soil’s expansiveness is significantly influenced by the initial water content and pore structure characteristics. The final expansion ratio is correlated with the water absorption characteristics of soil mineral particles. Additionally, changes in water content and dry density can significantly impact the resistivity index. The strong sensitivity between resistivity index and soil water content, along with the characterization of water absorption capacity in expanded soil minerals, suggests that the resistivity index is a valuable tool for assessing the expansion behavior of in situ expanded soil. Based on this foundation, resistivity, dry density and water content were normalized. A comprehensive indicator Q, which combines normalized water and electricity data, was introduced. Furthermore, an evaluation model for the non-loaded expansion ratio of in-situ expansive soil was developed. Through validation with existing experimental data, the proposed electrical evaluation model for the expansion ratio of in-situ expansive soil exhibits direct and efficient attributes, offering a dependable assessment of the expansive potential of in-situ expansive soil.更多还原