Unfrozen water model based on adsorption and capillary coupling effect

Abstract

The invention relates to an unfrozen water model based on adsorption and capillary coupling effect, which is prepared by the following steps: (1) collecting a soil sample, measuring the specific surface area AS of the soil and the humidity at room temperature, and taking the humidity of the soil at room temperature as the initial water content w0; (2) establishing an unfrozen water content model, and calculating the unfrozen water content wu; the method has the advantages of simple expression, few input parameters, convenience in calculation and deeper theoretical basis.

Description

technical field [0001] The invention relates to frozen soil engineering, in particular to an unfrozen water model based on adsorption and capillary coupling effects. Background technique [0002] Climate warming directly affects the freeze-thaw cycle of permafrost. The essence of the freeze-thaw process is ice-water phase transition and water migration. The freeze-thaw cycle will lead to the redistribution of soil moisture and solutes, change the thermal and hydraulic conductivity of the soil and microbial activity, and cause local soil heaving and thawing. Therefore, the modeling of unfrozen water content to describe the freeze-thaw process is the key to simulate and predict the ecological and hydrological changes of permafrost regions under the background of climate warming, as well as to calculate the structural strength of permafrost. [0003] According to the causes of unfrozen water and the freezing characteristics of unfrozen water (also known as soil freezing charac...

AI Technical Summary

Problems solved by technology

Most theoretical models are too complex to apply

The semi-empirical unfrozen water model has simple expressions and is convenient for calculation, but the parameters of most theoretical models and semi-empirical models (such as: initial moisture content, residual unfrozen water content, soil freezing characteristic curve shape factor, etc.) are not universal The expression needs to be obtained from unfrozen water experiments on the target soil, and these fitting parameters vary greatly for different soil types

Therefore, in permafrost areas with inconvenient transportation (such as the Qinghai-Tibet Plateau, the Arctic, and Alaska), there are only a few unfrozen water models that can calculate the unfrozen water content based on easily available parameters such as soil temperature and soil texture, and these The results of the model still need to be improved

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