Influence of rainfall infiltration on slopes by physical model test

By constructing physical models for slopes with different slope angles and experimentizing under artificial rainfall, variations of the slopes are monitored by layers continuously. The water content of the soil measured by water sensors buried in different places of the slope and the strain at different depths of the slope determined by optical fiber sensors are obtained, and the pressures at different depths at front end of the slopes are measured by pressure cells. The varation of monitored indexes of the slopes are obtained as follows: ①The water content of the slope, the pressure at front end of the slope, the strain of the slope body increase under the rainfall, and decrease with time after rainfall. ②Under the rainfall, the water infiltrates from the slope surface to the bottom; the greatest change of water content appears nearby the slope surface and the least change appears nearby the slope bottom; the influence of rainfall on the pressure at front end of the slope and the strain of the slope body gradually decrease with the increasing depth of the slope, that is, the influence near the surface layer is the largest, and that near the bottom layer is the least. It can explain why the failure of homogeneous soil-slope induced by rainfall is easy to occur in shallow layers. ③Under the same rainfall, the variations of the slope model with the slope angle of 20°are larger and occur relatively later; the variations of slope model with the slope angle of 10°are smaller, and occur relatively earlier.