Abstract:
In order to study the adsorption and migration of water vapor in remolded unsaturated loess, water vapor was used to humidify unsaturated loess, and the law of water-heat movement in remolded unsaturated loess
under vapor pressure gradient, temperature gradient and water content gradient was analyzed. The results show that the diffusion range of water vapor and temperature is similar to an ellipsoid in unsaturated loess. During the migration of water vapor, the water vapor pressure disappears along the radial direction, the vapor transport rate decreases, and the soil moisture content and temperature also reduce; when the vapor pressure is 0.1 MPa and the temperature is 145 ℃, the maximum humidification radius of water vapor is 80 cm, and the effective humidification radius in horizontal direction is 60 cm and that in vertical directions is 70 cm after 6.5 hours. In the ellipsoid with the point of ventilation as the center, with 40 cm in the horizontal direction and 50 cm in the longitudinal direction, the water content varies between 12% and 17%. The humidification effect is better, the moisture content close to the soil is 17.08% which is the optimum moisture content, the ventilation time is extended, and the humidification range and the humidification degree are increased; when the steam is humidifying, the migration of liquid water and the gaseous water coexist, but the migration of gaseous water is dominant within the effective humidification range. Obstructed by soil particles, the water transport rate decreases gradually along the radial direction, but the temperature conductivity is close to a fixed value in two stages; the steam humidification method is a new technology and a new method for soil humidification. The advantages have broad application prospects in the engineering practice and experiment of soil humidification.