Fig 1.
Schematic diagram of the experimental device.
(1. temperature sensors, 2. volumetric water content sensors, 3. displacement sensor, 4. metal block, 5. soil column, 6. weighing sensor).
Fig 2.
Physical photograph of the experimental device.
(a) plexiglass cylinder, (b) temperature control equipment, (c) peristaltic pump, (d) data acquisition instrument, (e) weighing sensor.
Fig 3.
Schematic diagram of some details.
(a) soil column: ①infiltration channel, ②antifreeze circulation channel, ③filter paper, ④porous metal sheet, ⑤outflow channel; (b) porous metal sheet; (c) cross recess.
Fig 4.
Schematic diagram of the soil column.
(a) H, (b) HI, (c) P.
Fig 5.
Grain size distribution.
Table 1.
Experimental conditions.
Table 2.
Experimental parameters.
Fig 6.
Schematic diagram of the initial state of the soil column.
Fig 7.
Schematic diagram of soil column division and the sensor distribution.
(The rectangle represents the moisture sensor, and the circle represents the temperature sensor).
Fig 8.
Variations of volumetric water content (Δθ) at the bottom of H for different temperature gradients.
Fig 9.
Variations of volumetric water contents (Δθ) at different positions of HI for different temperature gradients.
(a) top part, (b) middle part, (c) bottom part.
Fig 10.
Variations of volumetric water contents (Δθ) at different positions of P for different temperature gradients.
(a) top part, (b) middle part, (c) bottom part.
Fig 11.
Water distribution of HI and P at 120h at different temperature gradients.
Table 3.
Outflow time of HI and P at different temperature gradients.
Fig 12.
Variations of temperature at the same position in different soil columns at 5–20°C.
Fig 13.
Variations of temperature at the same position in different soil columns at 5–35°C.
Fig 14.
Temperature distribution of H, HI and P in different temperature gradients at 120 h.
(a) 5–20°C, (b) 5–35°C.
Fig 15.
Variations of top displacement of different soil columns for different temperature gradients.
(a) H, (b) HI, P.