基于阻抗谱的土石体电阻相似性孔隙特征研究

Study on pore characteristics of soil-rock mixture resistance similarity based on the electrochemical impedance spectroscopy

基于电化学阻抗谱(EIS)Nyquist图像的分布特征,依据土石混合体的电阻相似性对孔隙特征进行了研究。基于Nyquist图像分布特征与土石混合体的含水率、土石比和石粒粒径等因素的对应性关系,提出了分布特征点、分布特征角tanθ、分布特征曲线、孔隙特征最优点等新概念及方法,得出:含水率、土石比、石粒粒径对土石体孔隙特征的影响依次减弱;土石体关于电阻相似性变化的含水率阈值为12%,土石比阈值为7∶3,小于比值时会对其电阻相似性起抑制作用;石粒粒径影响土石体中颗粒接触构成时改变了其颗粒不均匀程度,两种影响程度的相对强弱以土石比7∶3,石粒粒径6~8 mm为阈值;孔隙特征最优点可作为土石体孔隙特征的评价工具。

Based on the distribution characteristics of the Nyquist image of electrochemical impedance spectroscopy(EIS), the pore characteristics are studied, which also relies on the resistance similarity of the soil-rock mixture. The corresponding relationships between the distribution characteristics of Nyquist images and the water content, soil-stone ratio and stone particle size of soil-rock mixture are utilized to propose a series of novel concepts and methods, including characteristic points of impedance spectroscopy distribution, distribution characteristic angle, distribution characteristic curve, ideal tanθ curve of distribution characteristic angle, and optimal point of pore characteristics. The influence of water content, soil-stone ratio, and stone particle size on pore characteristics of soil-rock mixtures decease in turn. The water content threshold of the soil-rock mixture concerning for to the change in resistance similarity is 12%. The threshold of the soil-stone ratio is 7∶3. And the resistance similarity of the soil-rock mixture is suppressed when the ratio is smaller than this ratio. The stone particle size affects the composition of the particles in the soil-rock mixture and changes the heterogeneity of the particles in the soil-rock mixtures system. The relative strength of two impact levels is based on a threshold of 7∶3 for the soil-stone ratio and 6~8 mm for the stone particle size. The optimal point of pore characteristics can be used as a metric for evaluating the pore characteristics of soil-rock mixtures.