土壤交流电阻率与其化学风化程度的关系

利用交流电桥研究了含水率和电流频率对土体电阻率的影响,并探讨电阻率与土体的化学风化指数CWI的关系.试验结果表明,土样的电阻率随着含水率和电流频率的增加而减小;当含水率低时,随着含水率的增加,电阻率快速降低;当含水率高时,随着含水率的增加,电阻率的降幅较小;而电流频率引起的降幅较小;基于风化程度与电阻率正相关的观点,建立了电阻率与化学风化指数的关系式,并给出了拟合参数的计算方法;拟合公式预测的化学风化指数值与实测数值基本吻合,可为风化程度的评价提供参考依据.

Relationship Between AC Electrical Resistivity and the Degree of Soil Chemical Weathering

By using alternating current(AC) bridge， the effects of the water content and electric current frequency on the electrical resistivity of soils were studied to investigate the relationship between resistivity and soil chemical weathering index (CWI). The test results show that the electrical resistivity of soils decreases with the increase of water content and electric current frequency. When the water content is relatively low， the electrical resistivity decreases very sharply with the increase of water content， but turned slowly at relatively high water content. However， the electrical resistivity has only a smaller reduction with the increase of the electric frequency. Based on the viewpoint of that the weathering degree is positively related to the electric resistivity， the relationship between resistivity and chemical weathering index was established， and the computing method for fitted parameters was given. A comparison between CWI predicted by fitted equation and actual CWI was made to show its reliability. The electrical resistivity can provide reference for the evaluation of the degree of weathering.