The laboratory test of unsaturated remolded kaolin showed that the relationship between resistivity of the sample with different porosity ratios and its matrix suction could be fitted with a power function and that the electrical resistivity is related to the air-entry value and the saturated state ( Cardoso and Dias, 2017). The laboratory test of unsaturated compacted loess showed that the resistivity of the sample had a linear relationship with the matrix suction under different degrees of compaction ( Zhu and Zhang, 2018). When the matrix suction is below 10 kPa, the matrix suction is linearly related to the electrical resistivity and thereafter exhibited a complex non-linear relationship ( De Vita et al., 2012). Laboratory tests of shallow unsaturated landslide soil with volcanic ash deposits showed that there were two functional relationships among resistivity, water content, and matrix suction under different grain sizes.
Previous studies have shown that certain functional relationships exist between matrix suction (or soil water potential) and electrical conductivity (or resistivity) for different unsaturated soils ( Qin et al., 2020). Considering that the magnitude of suction also depends on the water content ( Lu et al., 2014), there could be some connection between the matrix suction and the electrical conductivity of unsaturated soil. For unsaturated soils with similar particle composition and pore water chemical composition, the electrical conductivity mainly depends on the change of soil moisture content ( Chen et al., 2006). Measurement of suction, based on laboratory tests, requires a high standard of operation, which is time-consuming, expensive, and complicated ( Delage et al., 2008), and it is even harder to measure the field matrix suction.Įlectrical conductivity is one of the inherent properties of soil. However, the quick and accurate measurement of soil suction is an urgent problem to be solved. It is the basis and core concept of the unsaturated soil mechanics theory system ( Van Genuchten, 1980 Lu and Griffiths, 2004). The suction of unsaturated soil is an important index to characterize its engineering properties ( Zhang, et al., 2022). Unsaturated soil is widely distributed in nature and is involved in most of the geotechnical problems ( Fredlund and Rahardjo, 1993 Lu and Likos, 2006).
Its feasibility is verified based on field tests, which is of great significance to landslide monitoring and early warning. (3) The relationship between the conductivity parameters of the residual soil slope and matrix suction is further revealed and a new method to indirectly measure matrix suction is proposed. The suction contour map shows a parabola shape with the opening downward. The matrix suction is distributed in layers on the profile and its recovery rate is slower than saturation. (2) Under artificial simulated rainfall, the saturation, hysteresis of the conductivity parameters, and matrix suction response of the slope occurs, which is controlled by soil depth, permeability and rainfall intensity. By considering the above parameters, the comprehensive structure parameter R e is introduced and its functional relationship with matrix suction is established. The results show that: (1) The transverse conductivity, average structure factor, average shape factor, and anisotropy coefficient of unsaturated soil are related to the soil saturation degree. Based on the proposed model, the matrix suction distribution of on-site soil slope is predicted and the dynamic response law under the influence of artificial rainfall is studied. Through physical and chemical property analysis, soil-water characteristic curves and electric parameter matrix suction prediction models for unsaturated granite residual soil at different depths of the target area are obtained. To study the relationship between matrix suction and conductivity in unsaturated granite residual soil and realize the matrix suction prediction of soil slope based on conductivity, laboratory and field tests are carried out on undisturbed soil at different depths of the Yandou village landslide in Sanming City, Fujian Province, China. 3Engineering Research Center of Geological Engineering, Fuzhou University, Fuzhou, China.2Engineering Science Department, Andres Bello University, Santiago, Chile.1Zijin School of Geology and Mining, Fuzhou University, Fuzhou, China.Ruimin Chen 1, Yunzhao Lin 1, Qingling Liu 1, Hongqiang Dou 1, Luis F.
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