Method for determining unfrozen water content of frozen soil through measuring electrical resistivity

Abstract

The invention provides a method for determining unfrozen water content of frozen soil through measuring electrical resistivity. The method comprises the following steps: preparing a cylindrical saturated soil sample by utilizing a PVC (Polyvinyl Chloride) plastic pipe; respectively determining the volumes of soil particles and pore water in the saturated soil sample; determining cross sectional areas of the soil particles and the pore water in the saturated soil sample; freezing the saturated soil sample in a low-temperature test box, uniformly smearing the upper and lower circular surfaces of the cylindrical saturated soil sample, and measuring the resistance of the cylindrical saturated soil sample by using a multi-meter; calculating the electrical resistivity of the saturated soil sample at each temperature; drying the determined saturated soil sample in a drying box, determining the resistance of the dried saturated sample soil, and calculating the electrical resistivity of the dried saturated soil sample; calculating the volume of the unfrozen water of the saturated soil sample until the unfrozen water content is calculated. The method has the beneficial effects that the unfrozen water content of the frozen soil at different negative temperatures can be obtained; a calculating result is accurate and reliable; the measurement error of the method is within 2.4 percent; the test accuracy of the unfrozen water of the frozen soil is ensured; convenience can be provided for temperature field calculation in frozen soil engineering construction.

Description

technical field [0001] The invention belongs to the field of geotechnical engineering of the subject of civil engineering, specifically relates to determining the unfrozen water content in frozen soil by measuring resistivity, and is mainly applied to the determination of unfrozen water content in natural frozen soil or artificial frozen soil. Background technique [0002] With the rapid development of the world economy and the continuous growth of the population, the world is demanding and looking for more living space. Therefore, the development of underground space has become an important way for human beings to expand their living space. Since my country's reform and opening up, the economy and science and technology have developed rapidly, and our country has gradually realized the importance of the development and utilization of underground space. Construction companies have encountered many engineering problems in permafrost in the development and construction of vas...

AI Technical Summary

Problems solved by technology

In laboratory tests, it was found to be in good agreement with the results determined by calorimetry, but the equipment of NMR method is expensive and the test time is very long

③ Time-domain reflectometry (TDR), developed according to the significant changes in the dielectric constant of ice and water in frozen soil, this method is simple to operate, but research shows that the dielectric constant of soil is easily affected by soil quality, temperature and weight, etc. The influence of physical factors

[0004] The main problems of methods ① and ② for the determination of unfrozen water are that the operation process is very complicated, the test time is too long, and the equipment is expensive.

The main problem of the third method of measuring unfrozen water is that the error is too large

The error of the unfrozen water content measurement results is too large, and the hydraulic, thermal and mechanical properties of the soil cannot be accurately analyzed

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