Laboratory Model Test on Moisture-Heat and Deformation Behaviour of Red Clay Slope under Action of Rainfall and Sunlight

Abstract

Taking the red clay of Guizhou as the test material, the moisture-heat and deformation behaviour of red clay slope under action of rainfall and illumination were studied by constructing model slopes, observation systems, artificial rainfall systems and sunlight systems. The results showed that the volume moisture content decreased continuously during the sunlight period and decreased slowly after 5 days of sunlight, but it increased sharply during the rainfall period and the increments decreased with the increase in depth. The volume moisture content of the slope crest had almost the same increments after each rainfall; the volume moisture content of the slope surface increased slightly after the first rainfall, and then increased significantly thereafter; and the volume moisture content of the slope toe increased significantly after the first rainfall, and then increased slightly. The migration of water and heat in the soil showed a strong coupling. In other words, the temperature change could indirectly reflect the volume moisture content change, and the volume moisture content change would promote the redistribution of temperature. The depth effected by everyday sunlight and rainfall on temperature were both less than 42cm. Rainfall mainly affected the horizontal displacement of the shallow soil of the slope, and the horizontal displacement of slope toe is the largest, followed by slope surface and the smallest at the slope crest.