In order to characterize water redistribution and gas-heat diffusion of reconstruction soil filled with gangue in coal mining areas

guide engineering design and rebuild soil ripening technology

a simulator was designed in laboratory. Soil water content

temperature and soil CO2 concentration could be constantly measured by laid sensors and detectors in different depth of soil column. The results showed that soil water infiltration process was slowed down and the water-holding capacity of the upper soil was increased because of good water resistance from coal gangue layer. However

the water content of coal gangue layer was significantly lower

approximately 10%

than that of topsoil due to the poor water-holding capacity of gangue. Coal gangue had higher thermal diffusivity

higher temperature than that of topsoil with heating

could form sustainable temperature gradient and temperature difference with topsoil layer in reconstruction soil. The effects of heated from below on topsoil was small

which it was mainly influenced from indoor temperature in the short run. In addition

the temperature changing curve of topsoil is similar with the temperature of laboratory and its biggest fluctuation range was for 2.89 ℃. The effects of aerating CO2 from column bottom on CO2 concentration of topsoil soil was also very small

because gas transport from coal gangue layers to soil ones would easily be cut off as so to gas accumulated in the soil layer below. The coal gangue could have a negative impact on microbial living environment to adjacent topsoil layers and declined microorganism activities. The effects of coal gangue on topsoil layer were brought down when the cover soil thickness was 60 cm. The influences gradually would be weakened with the thickness increased.