摘要
基于电极间压强对电化学阻抗谱测试的影响,提出用阻抗谱特征参数来表征粉质黏土的压缩特性和压敏性的方法。该方法通过测试粉质黏土在不同电极压强下的电化学阻抗谱和压缩指标,经过等效电路拟合,利用其参数来解释其压缩过程,并将电极间压强与其图谱的三大典型特征指标:Nyquist图与阻抗实部截距及其低频圆弧直径和Bode图波峰处相位角的比值与粉质黏土孔隙比相联系,分别得出其各自的压缩系数。研究表明:含水量为12%的粉质黏土阻抗谱呈现非Randles模型,随着电极间压强的增大,其等效电路参数溶液电阻、电荷转移电阻不断减小,双电层电容不断增大;Nyquist图、Bode图最高点向低频移动,测试结果更精确、稳定;图谱特征参数的压缩系数不断减小。研究表明,电化学阻抗谱与压敏性有必然的联系,并且可以利用阻抗谱特征参数的压缩系数来衡量粉质黏土的压缩特性及其压敏性。
Based on the influence of pressure between electrodes on the electrochemical impedance spectroscopy （EIS） , an evalua-tion method of compressibility and compression sensitivity of silty clay using EIS characteristic parameters was developed in this study. EIS and compression index of silty clay under different pressure between electrodes were tested and equivalent circuit fit-ting was performed. The parameters attained from the equivalent circuit were used to interpret compression procedure. The ratio of the pressure between electrodes and three typical characteristic parameters （i. e. , intercept between and impedance real part, low frequency circular diameter of Nyquist diagram and wave phase angle of Bode diagram） of diagram were related with silty clay void ratio and correlated compression coefficients were calculated. The test results showed that the impedance spectrum of the silty clay sample with a moisture content of 12% impedance spectrum fits the Randles model. As the increase of the pressure be-tween electrodes, solution resistance and charge transfer resistance decrease, while the capacitance of electric double layer increa-ses continuously. The peaks of Nyquist diagrams and Bode diagram move to low frequency region, which makes a great contribu-tion to the accuracy and stability of the test result Compression coefficients of spectroscopy typical characteristics decrease with the increasing of pressure between electrodes. This study showed that there was good relationship between EIS and compression sensitivity. Compression coefficients of impedance spectrum characteristic parameters can be used to evaluate the compressibility and compression sensitivity of silty clay.
出处
《中国科技论文》
CAS
北大核心
2016年第13期1530-1533,共4页
China Sciencepaper
关键词
电化学阻抗谱
压敏性
Nyquist图
BODE图
等效电路
electrochemical impedance spectroscopy （EIS）
pressure sensitive
Nyquist diagram
Bode diagram
equivalent circuit
作者简介
王茂桑（1963-）,男,高级工程师,主要研究方向为岩土工程,13603565858@139.com
